I am doing lead conversion process. Is it possible to convert the lead without creating the account record?
No. Lead conversion always includes at a minimum the creation of an Account and a Contact. Creation of the Opportunity is optional.
If you wanted to remove the Account, you would be required to delete the account after the fact. But this can have ramifications on visibility of the Contact record in the future, so be certain to test record visibility if you decide to go that route.
You can read more about it in the online help.