Ibrahimovic, PSG's marquee summer signing, has scored five goals in Ligue 1 this season, but the Swede is well aware that Tuesday's opening Group A game at home to Dynamo Kiev will be a difficult test.
"We'll see the level difference between the league, any (domestic) league, and the Champions League," Ibrahimovic, who moved from AC Milan, told a news conference on Monday.
He was joined by former Milan team mate Thiago Silva, who will make his PSG debut on Tuesday, as well as Argentine forward Ezequiel Lavezzi as the Qatar-backed French club spent over 100 million euros on transfers in the close season.
"I can already see a difference between the day I came here and now," said Ibrahimovic, who has never won Europe's premium club competition.
"The Champions League is a competition that makes a team become better."
PSG should be strong enough to progress from a group also featuring Porto and Dinamo Zagreb, but Ibrahimovic is taking nothing for granted.
"The quality is here, the potential is here," he said.
"But the Champions League is difficult. It doesn't matter which team you play because even if they are not Barca or Real, they are still good. We do not underestimate anyone in the group. Whether we are the favourites or not is not important."
Coach Carlo Ancelotti said that even though PSG have not played in the Champions League for eight years, they have a squad to cope.
"We have a lot of experienced players, and also an experienced coach," the Italian, who confirmed that Thiago Silva would start in central defence after overcoming a thigh injury, said with a grin.
PSG will be without centre back Mamadou Sakho, who picked up a minor injury in their 2-0 win over Toulouse at the weekend, and Dutch fullback Gregory van der Wiel, who is not fit to play after joining last week from Ajax Amsterdam.
Dynamo Kiev should be able to call on forward Andriy Yarmolenko who has shrugged off an injury he picked up during Ukraine's 1-1 draw against England in a World Cup qualifier last week, according to coach Yuriy Syomin.