Congressional Black Caucus members said this week it is time to stop talking and start doing something about the mounting list of black officials who have been investigated, indicted or convicted in what many black leaders view as a clear pattern of government harassment and selective law enforcement.

At the caucus's annual conference here, Rep. Mervyn M. Dymally (D-Calif.) urged black political organizations, research groups and churches to establish a "formal institution charged with seeing that the right of African Americans to be represented before the governmental bodies of our land will no longer be abridged by systematic harassment of black officials."

The organization, a Dymally aide said, would raise funds and help develop defense strategies.

Rep. John Conyers Jr. (D-Mich.), chairman of the House Government Operations Committee and the second most senior member of the 24-member caucus, announced that he will hold hearings on the harassment issue sometime next year. The hearings, Conyers said yesterday in an interview, would look at the tactics government investigators use in bringing cases against black officials, the numbers of cases that have been brought, and their outcomes.

"What we're trying to do is take the emotional content and rhetorical factor out of it as much as possible," Conyers said.

The claim of harassment and selective law enforcement has been fueled by criticism of the law enforcement tactics used in such high-profile cases as that of D.C. Mayor Marion Barry, filmed in an FBI sting operation then convicted last summer on a drug charge; House Majority Whip William H. Gray III (D-Pa.), the subject last year of a leak claiming he was the target of a Justice Department investigation, later denied by the department; and Los Angeles Mayor Tom Bradley, who was investigated but not prosecuted for financial improprieties.

These accounts and numerous others detailing an alleged pattern of discrimination have been recounted in a series of meetings on the subject at the caucus's annual Legislative Weekend, which began Thursday. The annual gathering is attended by thousands of blacks, including state and local officials, educators and church men and women.

Participants in the meetings argued that black officials, who comprise about 2 percent of all elected officials, appear to be disproportionately targeted by both law enforcement and the media.

Dymally, who was the subject last winter of press reports alleging an apparent conflict of interest on sanctions against South Africa, said that 15 years ago he began seeing "small parts of a pattern" that over the years has fed "a growing perception among African Americans that black elected and public officials are being singled out for harassment."

"It is a perception that demands the most serious attention because it calls into question the ability of African Americans to participate fully in the process of American self-government," Dymally said.

The meetings were attended by hundreds of blacks at the caucus conference, who heard a drum-beat of harassment horror stories: black officials who were said to have been subjects of surveillance, wiretaps and videotaping; black officials offered bribes by people the officials believe to be undercover FBI agents; black officials going bankrupt to pay for legal defenses.

"It's necessary to react early . . . because you've got to help define the issue," said Alabama State Sen. Hank Sanders. "The defense has to be a comprehensive one," he said, including community support and public relations as well as legal. "You have to define the attack as an attack on {black} leadership," he said.

Justice Department officials have consistently denied that black officials are specially targeted for investigation and prosecution. More than 5,000 public officials have been prosecuted by the department over the past 10 years.

Attorney General Dick Thornburgh has asked black officials to supply statistics to back up their claims. Asked by reporters to provide a racial breakdown of public officials investigated and prosecuted, he snapped, "Do you think it would make any difference?" A department spokesman yesterday said Thornburgh's position is unchanged.

In the absence of statistical evidence, the debate has been guided by anecdotes and perception, said Russell E. Owens, director of the National Policy Insitute. The result, he said, is that "nobody is looking at the issue accurately. What we have is a lot of sound and fury" that "is going to further divide us."

Absent, also, from the caucus's harassment hearings Thursday was discussion of the guilt or innocence of black officials in specific cases. That, said Owens, is not the issue.

"There is a larger issue: whether or not blacks are being treated fairly and equitably and whether they are given access to all the protections that are guaranteed them as citizens of the United States," he said.

Conyers said staff assistants already are researching the issue in advance of his hearings. He said part of the process will involve ferreting out cases that are not appropriate.

"Everyone that makes the claim, that doesn't mean it's automatically accurate," Conyers said. "The flag and motherhood are the last refuge of every scoundrel. So we're not naive about this. This is not something where we go in saying everything everybody says about racism is automatically correct. We're really trying to introduce as much scientific understanding of the subject as we can."