The clerk of the Montgomery County Circuit Court told a testimonial dinner audience of over 200 county government officials and employees a racial joke equating District Mayor Walter E. Washington and aide Joseph P. Yeldell with a pair of black loafers.

The joke has drawn a personal protest from the executive secretary of the county's Human Rights Commission as well as others who were present at the dinner held for a retiring county employee Friday night. Among those prominent officials attending were at least one judge, one county councilman, and a staff member of County Executive James P. Gleason, sources said.

The clark, Howard M. Smith, acknowledged last night telling the joke, but said, "There were no racial implications behind it. I'm shocked that somebody took offense to it."

Smith said a reporter's call was the first indication he had that some took offense to the joke. He said the joke was "not original," but told to him by a black man.

According to those present, Smith told the audience that President Carter, after sending White House press secretary Jody Powell for a pair of black loafers, fired Powell when he returned with Yeldell and Washington.

Two of the three persons interviewed about the incident, county budget analyst Donald Gibson and County Council Neal Potter, said about half the audience responded with "polite laughter" and half sat stunned at what Potter called "a tastless joke."

I thought it was very inappropriate for a public official to make such a comment," said Gibson, a member of the county's minority employees association. "(Every speaker) has been making jokes - it was a light-hearted occasion - but . . . nothing like this."

Alan P. Dean, Executive secretary of the county's Human Relations Commission, who also was present, said Smith's telling such a joke was worse than the racial slur former Agriculture Secretary Earl Butz made against blacks.

"Butz told his (joke) in private conversation," Dean said. "This was told before 200 people in a public speech."

Dean said he is writing a letter of protest about the incident. He said he plans to send it to County Executive James P. Gleason and Smith.

Dean said those sitting near him were "stunned" by the joke. "There was no laughter. You could hear a pin drop."

Whatever the audience reaction, all three men said Smith apparently thought nothing was wrong with the joke and continued telling jokes and praising the retiring employee for another five minutes.

Montgomery County State's Attorney Andre Sonner said when contacted late yesterday that he hadn't heard of the incident, but said that a "rap of racism on Smith is unjustified.

"I know Howard Smith real well," Sonner said. "If he entertains any bigoted thoughts, he's hid them from me." Sonner said Smith was one of the first in the courthouse to hire a black employee.

A spokeswoman for Mayor Washington said they would have no comment on "that kind of garbage." Neither Yeldell nor a spokesman for him could be reached for comment.

Smith's professional reputation is that of an efficient administrator who has improved the Cuonty Courthouse's record-keeping system, Potter said. As clerk, he supervises the filing of all land records and court records.

Smith said he supervises about 120 employees in the clerk's office. Two of those employees, he said, are black. He said he didn't know if that was a "normal" ratio of black to white employees in the courthouse, but said he was the first in the courthouse to hire a black employee in about 1968. Smith was first elected to the post in 1966.