Manuel Pellegrini's side won the Premier League title and the Capital One Cup in the Chilean's first season at the club, but they were knocked out of the Europe's top competition in the last-16 stage by Barcelona.
Kolarov told Sky Sports News: "Of course it's possible for us to improve next season. We have a team who will to try and win the Premier League again and to do something much better in the Champions League.
"This season we have improved a lot. We've had more experience in the group and the new manager has also brought in his experience.
"At the end of the season we are very happy to win two trophies. The bosses know what we have to do [in the transfer window] so they will do the right job."
The 28-year-old made 44 appearances for City in all competitions last season, scoring four goals.