That total means Messi is now 99 goals clear of Barca's second-highest scorer Cesar Rodriguez, while the Argentine has broken a series of other records during his time at Camp Nou, as well as winning four Ballon d'Or prizes and an astonishing 21 team trophies.
Those include six Liga titles, three Champions League crowns, two Copas del Rey, two UEFA Super Cups and two Club World Cups. And of the current squad at Barca, only Xavi (who is reaching the end of his playing career and is 34 this week) has won more than that thanks to the Primera Division title he won under Louis van Gaal in 1999.
With a large part of his career still ahead of him - and given his intention to spend most or all of that at Camp Nou - Messi looks set to build on his already remarkable record. So here, as he prepares to make his 400th appearance for the Blaugrana, Goal takes a look at the most memorable matches - in chronological order, from 1 to 400 - of the forward's fantastic playing career at Barcelona.
5 - Plays 90 minutes for the first time in his Champions League debut, a 2-0 defeat in a dead rubber at Shakhtar Donetsk in Dec. 2004.
9 - Comes on as a late substitute at home to Albacete in La Liga and scores his first goal for Barcelona, a neat lob with his left foot after being set up by Ronaldinho. Moments earlier, he had seen a similar effort incorrectly ruled offside.
16 - Messi's maiden Champions League goal comes in a 5-0 win at home to Panathinaikos. Samuel Eto'o hits a hat trick and Mark van Bommel scores the first after just a minute.
18 - Leo's first Clasico against Real Madrid is a memorable one as Barca wins 3-0 at the Santiago Bernabeu and Ronaldinho is given a standing ovation by the home fans following his two stunning strikes. Years later, Messi would torment Barca's biggest rival with comparable brilliance of his own.
32 - Messi goes down under a strong challenge from Chelsea's Asier del Horno and the Spanish defender is sent off, leaving Blues boss Jose Mourinho furious. "Barcelona is a cultural city with many great theaters and this boy has learned very well. He's learned play acting," the Portuguese said. Barca wins 2-1 and Messi later replies: "I don't do theater."
34 - Heartache for Leo as he tears a muscle in his right thigh and limps off in tears as Barca draw with Chelsea. The Catalans go on to win La Liga and the Champions League, but Messi is sidelined for the rest of the season.
57 - The Argentine hits a brilliant hat trick in his first-ever Clasico at Camp Nou as Barca comes back three times from a goal down to draw 3-3 with Fabio Capello's Real Madrid.
62 - Comparisons with Diego Maradona continue as Messi scores a carbon copy of his compatriot's famous second goal against England in the 1986 World Cup by beating a number of Getafe defenders and running half the length of the pitch to net one the most special strikes ever seen at Camp Nou. Leo also smashes another into the top corner with a fine finish in the 5-2 Copa win - but nobody remembers that one.
69 - Messi scores twice, including one with his hand in another goal which draws comparisons with Maradona, in the 2-2 draw at home to Espanyol, a game remembered for Raul Tamudo's double which effectively ends the Blaugrana's hopes of retaining the title for a third year running.
100 - Leo's 100th game for Barca is not particularly memorable as the Catalans can only draw at home to Valencia in the semifinals of the Copa del Rey - and that thanks to a late, late leveller from Xavi. Valencia goes on to win the competition as Frank Rijkaard's side ends the season without a trophy.
157 - Guardiola springs a surprise in a virtual title decider at the Bernabeu as he starts Messi in the center of his side's three-man attack. The Argentine scores twice in a historic 6-2 win and fans of the Catalan club are given a glimpse of what is to come.
160 - Messi scores as Barca beats Athletic Bilbao 4-1 to win the Copa del Rey, the team's first trophy under Pep. Days later, La Liga follows.
161 - The Argentine wins the duel with Cristiano Ronaldo and nets for the first time against English opposition as he heads the second against Manchester United in a 2-0 win. More importantly, Barcelona claims the Champions League and completes a historic treble in Guardiola's first season as coach of the Catalan club.
162 - Another game, another trophy: Messi nets twice as Barca beats Athletic 3-0 to claim the Spanish Supercopa.
184 - Barcelona makes it six titles out of six under Guardiola by winning the Club World Cup. In the final against Argentine side Estudiantes, Messi chests home the winner in extra time.
199 - Leo scores three in a 4-2 win at Zaragoza and becomes the first player to net back-to-back Liga hat tricks for the Catalan club. He had also hit a treble against Valencia the previous weekend.
200 - The forward makes his 200th appearance for Barcelona in the Catalans' 2-0 victory at home to Osasuna. Zlatan Ibrahimovic and Bojan score the goals.
205 - The Rosario-born forward is on target again as Barca beats Madrid 2-0 at the Bernabeu to move clear of Real in the race for the title, which Barcelona retains by three points from Manuel Pellegrini's men.
210 - Player and club suffer disappointment as they miss out to Mourinho's Inter in the Champions League semifinal, despite a 1-0 win in the return at Camp Nou.
216 - Yet another hat trick sees Barca claim the Spanish Supercopa thanks to a 4-0 win at home to Sevilla (and 5-3 aggregate success overall).
231 - Messi scores three more as Guardiola's side smashes eight without reply past Almeria, coached by Pep's friend and mentor Juanma Lillo. After losing 8-0, however, Lillo is dismissed.
233 - Leo turns provider with two superb assists for David Villa as the Catalans thrash Mourinho's Madrid 5-0 in the Portuguese's first Clasico, in Nov. 2010. Xavi, Pedro and Jeffren are also on target.
250 - The Argentine nets a late winner to seal three points in a hard-fought 2-1 win over Athletic Bilbao at Camp Nou.
261 - The forward scores his first goal versus a Mourinho team, while Cristiano Ronaldo nets his first against Barcelona (both are penalties) as Clasico spoils are shared in the first of four meetings between the sides in 17 days, a 1-1 draw away to Real Madrid.
262 - Ronaldo heads the winner in the final of the Copa del Rey to give Mourinho's men the title. In the dressing room, Messi is in tears.
264 - Revenge comes just days later at the Bernabeu as the forward scores two stunning goals after Pepe's red card to all but decide the sides' Champions League semifinal in a 2-0 win.
269 - Messi is on target with a great goal and celebrates wildly as Barca beats Manchester United 3-1 in another Champions League final. Pedro and Villa also score for Guardiola's side in an emphatic victory.
272 - On target again as Barca beats Porto to win the UEFA Super Cup with a 2-0 victory.
281 - Messi bags a double to surpass legendary Hungarian Laszlo Kubala on the list of all-time scorers at Barcelona. "He deserves his own statue outside Camp Nou, like Kubala," Adriano says.
295 - Much is made of the match up with Santos and Neymar, but Messi wins the battle with his future teammate in a superb showing which includes two more goals and sees Barca claim the Club World Cup once again following a 4-0 win.
300 - Makes his 300th competitive appearance for Barca on Guardiola's birthday, Jan. 18, 2012, as the Catalans beat Madrid 2-1 in a Copa quarterfinal first leg at the Bernabeu.
309 - Nets four in a 5-1 victory over Valencia in La Liga.
311 - Hits five goals in an incredible performance as Barca thrashes Bayer Leverkusen 7-1 in the second round of the Champions League.
314 - Strikes three times in the 5-3 success over Granada to overtake Cesar Rodriguez (232 Barca goals) and become the Catalan club's all-time top goalscorer.
327 - Scores all four goals in a 4-0 win at home to city rival Espanyol in Guardiola's last home game as coach.
352 - Hits both in a 2-1 win at Betis in Dec. 2012 to reach 86 goals for club and country for that year, surpassing the previous record held by German great Gerd Muller. He ends 2012 with 91 strikes in total.
373 - His goal at Celta Vigo in La Liga means he has now netted consecutively against all of the teams in the Primera Division, a new record. It's the end of March but injury means Messi goes on to make just seven more appearances in the rest of the season. Barca wins La Liga, the team's only trophy in the sole season under Tito Vilanova.
400 - Despite two months out this term, Messi is set to make his 400th Barca appearance at Levante in the Copa del Rey on Wednesday.
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