The Blues are currently five points clear at the summit of the top-flight and have the chance to extend their lead when they visit Blackburn on Saturday.
The Italian knows his charges will have to up their game if they are going to hold onto their title and hopes to see an improvement.
"We have started the season well but I think we can play better because we played very well in some parts of some games but not continuously," he said.
"We have to play 90 minutes how we want to play. We have to improve our play and our intensity. We can't just play for 45 minutes like we did against Wolves.
"We want to play well for the whole of the match and we haven't been able to do that so far this season."
He added: "In the last two games away we didn't score against Man City and against Aston Villa.
"We had a good away game in the Champions League at Spartak Moscow but it is strange for us not to score away in two consecutive games in the Premier League.
"We had a fantastic performance when we won at Wigan 6-0 but we have to be better away."
Ancelotti knows his side face a tough test when they go to Ewood Park this weekend.
"It's very important to maintain that gap on the other teams," the 51-year-old remarked.
"Man City, Man Utd and Arsenal are interested in our results and they would like us to lose some points. For this reason it will be an important game tomorrow.
"If we are able to win this game I think that we can improve our confidence and we can give disappointment to the other teams."