Asked at a press conference if a win over world champions Australia in the home series would make India the top team, the skipper said "we have to match Australia in consistency.
"Australia have played good cricket over a period of time to become the number one team. We have played well and done well against them in Tests but in One-day cricket they have had the better of us. (But) doing well in the coming series will definitely close the gap."
Ganguly also advocated a two-tier system for preserving the game's standard if the International Cricket Council was to expand the number of Test playing nations to 16.
"The ICC has said that it is going to give six more countries Test status. But if the standard of the game has to be preserved, it would be better to have a two-tier system," said Ganguly, who is in New Delhi as part of a promotional visit.
The two-tier system would ensure that the world's strongest teams do not have to play against greenhorns.
ICC chairman Ehsan Mani had said during an Asian Cricket Council seminar at Lahore last week that the world governing body expected six more affiliated member countries to gain full membership by the year 2007.
Former captain Sunil Gavaskar, who was also present on the occasion, said, "The difference between the current Indian team and those of the past is that this team has won a Test series in Pakistan".
When asked about John Wright continuing as coach, Ganguly said, "It depends on lot of issues.
"John has been a very good coach. But whether to retain him or not depends on a lot of issues.
"He also has to decide. He has a family and he has been travelling widely for the last few years."