Joseph Webb, one of 15 trustees at the University of the District of Columbia, said yesterday that UDC President Robert L. Green should resign if he can't disprove the D.C. auditor's assertion that he has misspent thousands of dollars of university funds.

"If the president cannot prove he is innocent, I don't think he should be president," Webb said in an interview. "If the allegations cannot be disproved, the president should resign."

A trustee since April 1984, Webb is the first board member to speak out publicly about Green since the controversy about his expenditures began six weeks ago.

Gilbert Maddox, a spokesman for Green, said yesterday that "We have every reason to believe that Dr. Green can respond to the D.C. auditor in a positive and timely fashion.

"The question of resigning is not an issue that anyone at UDC has given consideration to," Maddox said. "On the contrary, we have been overwhelmed with nothing but affirmations of support from faculty, students and the total university community."

A draft report by D.C. Auditor Otis H. Troupe earlier this month concluded that Green, 52, had misspent at least $14,000 of UDC funds on travel, consulting fees and flowers that were for personal use.

The Washington Post reported last month that Green billed the university for trips to two funerals and a wedding and spent more than $80,000 on catering since taking over the presidency in September 1983. He is paid $74,900 annually.

Webb said, "Something is going to break and it's going to break in a very short time."

He said he was motivated to speak out because he is worried that "UDC is being embodied by a controversy about one individual."

"I am very concerned about people's perceptions of UDC," he said. "I want people to separate the man and the job."

Board chairman Ronald H. Brown, who played a key role in bringing Green here said the board is still reviewing information. Members are prepared to take any necessary action, but "only when we have all the facts," he said. Several other trustees also said they wished to review auditors' reports.

Board member Donald A. Brown, reached in Massachusetts by telephone, said, "Mr. Webb is enormously premature in making that kind of judgment."

Noting that the board has retained an accounting firm to make its own audit, he added: "I'm not going to prejudge anything or anybody." He said he is awaiting the firm's audit.

Trustee N. Joyce Payne said she was unaware of Webb's statement and declined to comment on it.

"I do think the board is anticipating the final report" from Troupe and "I am confident the board will take appropriate action on receipt of that," Payne said." . . . We take our governing role and oversight responsibility very seriously."

The board recently hired attorney Vincent Cohen, a prominent Washington lawyer, and Coopers & Lybrand, a national accounting firm, to review the audit.

Cohen 10 days ago wrote a letter on behalf of the board to D.C. City Council Chairman David Clarke complaining that Troupe had leaked information to the press and that he was biased against UDC.

Webb said yesterday that he disapproved of efforts by some board members and other UDC officials to discredit Troupe.

According to sources, several board members complained about the tone of a statement attacking Troupe's credibility that chairman Brown proposed to submit to The Washington Post for publication and the statement was never sent.