A football defender, Jancarlos de Oliveira Barros began playing in the youth club of Fluminense FC, in 1999. He then began playing professional football for the club in 2001. After over 40 appearances with the club, Barros was loaned out to Clube Juventude in 2004, where he spent a season. But at the end of the season, he moved to Atletico Paranaense, where he remained till 2008, making nearly 90 appearances with the team, and scoring 8 goals in the duration.
In 2008, Barros moved to his current club, Sao Paulo, with whom he has made over 10 appearances so far. Some of Barros’s title wins include Rio de Janeiro State League title in 2002 and the Parana State League title in 2005. Barros was also part of the winning team of the Brazilian top league title, in 2008.