The House proceeding begins Monday, and Rangel fired his legal team in October, ABC News reported.
Rangel, 80, denies all 13 counts of violating House rules. He is accused of failing to reveal more than $500,000 in assets on disclosure forms, improperly getting four rent-controlled apartments in New York City and failing to disclose financial arrangements for a villa in the Dominican Republic.
He also is accused of abusing his chairmanship to raise funds for the Charles B. Rangel Center for Public Service at City College of New York. He allegedly solicited corporations and foundations that had business before the Ways and Means Committee.
Rangel stepped down as chairman in March.
The trial is expected to last at least all of next week.
A subcommittee will vote on each of the 13 counts and report to the full ethics committee. The full committee then will hold a public hearing, and if any violation is found, vote on a sanction recommendation to the full House.