The Ivory Coast international spent three years at Barca before moving to City for a fee in the region of ?24million in 2010.
He told Spanish radio station RAC1: "I said two years ago that I would return. It's been the most important team for me and if they call you don't think twice. I love Barcelona."
Toure has been a big hit in Manchester and his two goals against Newcastle last weekend has put City on the verge of winning their first title since 1968, but the 28-year-old's long-term ambition remains a return to the Nou Camp.
He said: "In the press conference I did when I left I said I would return, in life you never know what will happen tomorrow, it's been the team of my life and I would like to finish my sporting career here. If I could return, it would be great."
Toure also believes Barca will be in good hands when Tito Vilanova replaces Pep Guardiola as coach this summer.
He said of Guardiola's decision to step down: "It was a little strange, because Guardiola has been a key person in the success of Barca in all these years. But we are all human and despite having done phenomenal things, he has decided to go.
"I know Tito very well and I think that he will apply the same philosophy as Pep. Tito is also a very good person, with a very similar idea of football. I think Tito is a good coach as well."