The Italian is quietly confident of his side's chances of defeating the Liga leaders when they meet in Europe
Les Parisiens triumphed over two legs against Valencia in the last 16, while the Blaugrana defeated AC Milan 4-0 at Camp Nou to overturn their 2-0 loss at San Siro in the first leg.
Ancelotti told reporters on Saturday: "We will have our chances. We will play against one of the best teams in the world, and it will be very exciting for us to prepare for this match.
"We will not be favorites, but I do not think an unbeatable team exists in football. We will do our chance to win.
"[Barcelona] is a great team with great individual qualities," he added. "On paper, Barcelona has more of a chance to reach the semifinals, but anything is possible, and this is what makes the beauty of our sport.
The former Chelsea boss insisted that his team must also be focused on its Ligue 1 campaign, starting with Sunday's clash with Saint-Etienne.
"We must remain focused and I expect to see significant effort against Saint-Etienne and in our home game against Montpellier. Then we can turns our heads to Barcelona."
Saint-Etienne has been impressive this season and sits fourth in the table, and Ancelotti had praise for its rise up the Ligue 1 standings.
"They work well because they have a very good coach, a very good tactician, who has established a good offensive and defensive organization," he said. "They are a complete team, and we must be careful."