Keita joined Barca in 2008 from Sevilla and he won 14 trophies during his time at Camp Nou, but was a more peripheral figure last season.
Though the Malian had two years remaining on his contract, he has triggered a reported clause in his deal allowing him to leave after failing to start in at least 50 per cent of the club's games last term.
"Seydou Keita announced tonight that he will not continue at the club next season," a Barca statement read.
"Barcelona would like to thank Seydou Keita for his role at the club in the last years and wish him new professional and personal successes in the future."
The 32-year-old is now widely expected to join several high-profile names in China, with reports suggesting he will sign a two-and-a-half year contract with Dalian Aerbin.
Towards the end of last season, Keita had been linked with the likes of AC Milan, Manchester United and Roma, but seems set to continue his career in the Far East.
http://www1.skysports.com/football/news/11095/7881037/Keita-quits-Barcelona