Many of yesterday's impatient radicals, who a decade ago were seeking immediate remedies to the nation's socials ills, have by now traded in their earthy blue jeans, tie-dyed T-shirts and love beads for the traditional conservatism of the three-piece business suit.

Thousands of those who marched, picketed and shouted slogans have disappeared into the mainstream of American life. Today, they are silent.

But Dick Gregory, black commedian, political activist and self-styled humanitarian, who became active during the 1960s in civil rights protests and later in the anti-Vietnam war movement, struggles on, maintaining his vigil against what he calls injustices, wherever they exist.

He still uses the nonviolent protest tactics of the '60s - even though most civil rights groups have abandoned them for the '70s - with the dogged determination of a prophet crying out in the wilderness, spurred on, he says, by be brighter for everyone.

"I know now that there is a universal force that controls the whole thing," Gregory once told an audience. "One day, it's all going to balance out on the ledgers and it's going to be a simple question. Not how much money did you make, not did people like you, but one simple question that all of us will have to deal with - just how much service did you give to your fellow man?"

His notion that he has a personal responsibility to dramatize what he calls world unjustices drives him on even though hundreds no longer join him in that effort and despite the fact that after years of self-announced hunger fasts, marathon cross-country runs, arrests and subsequent incarcerations, those publicity attempts draw little attention fromthe media now.

"I have a responsibility to myself to see to it that I do my share to help relieve conditions of injustice in America and the world," Gregory said recently in a telephone interview. "I don't want any man doing this nor me, I want to participate in making that dream come true."

In the 1960s, when thousands of people marched, picketed and were willing to be jailed to protest the lack of civil rights for blacks, Dick Gregory was with them, in towns like Selma, Montgomery and Jackson (Miss) - towns whose names were soon to be synonymous with the civil rights struggle in this country.

During the late '60s and early 1970s, Gregory set-aside a blossoming career as the nation's premiere black comedian - the first black to be well received by white audiences - to demonstrate and work full-time against the war in Vietnam and for other causes. Often, he was jailed.

This year, his protests have included picketing in front of the South African embassy here to dramatize the treatment of millions of blacks in that country.

He was arrested and jailed Oct. 18 in front of the embassy and was arrested and jailed three again on Thanksgiving Day.

The latter charge was dropped last week but Gregory, his wife and three others returned again yesterday to the embassy, located at 3005 Massachusetts Ave. NW. The five were arrested by D.C. police at 11 a.m. and charged with demonstrating which 500 feet of the embassy.

Gregory, his wife and two of the three other demonstrators refused to put up $50 in collateral and spent the day and night in jail, police said. Gregory said he hoped the charges will not be dropped this time because he wants to test the constitutionality of the city law that prohibits demonstrations within 500 feet of an embassy.

"A friend of mine sent me a clipping after I went to jail (last month) from a South African newspaper talking about why I went to jail," he said. "Just think about that - if Martin Luther King and other civil rights leaders had been able to see that blacks in other countries were protesting treatment, (by others) what a boost that would have been."

While othe civil rights groups may share some of the same causes as Dick Gregory, causes he says he chooses on the basis of "who is the under dog," many civil rights groups have apparently abandoned the tactics of marches, sit-ins and picketing as unproductive during the '70s.

"Every individual or organization has to decide its own strategy as to how that organization sees itself dealing with the problem," said Vernon Jordon, executive director of the National Urban League.

"One in my situation does not have a right to judge. Black people have a great deal of respect and commitment ot Dick Gregory, but that does not mean that one would join in and agree with his type of protest." Jordon said.

"(Marches, and demonstrations) will not be the Urban League tactics for the 70s," he said.

Gregory, 45, the father of 10 children, said he is committed to dramatizing and publicizing injustices even at the risk of sacrificing some of the needs of his family.

"This thing is bigger than me, my wife or my children," he said. Gregory declined to say what his income is but said he makes about 300 speaking appearances a year and receives additional income from the sale of his autoblography, "Nigger," and a health food book he was written. Gregory and his family lice on a 400-acre rented estate in Massachusetts.

He has known hardship, however, growing up poor and black in the ghettoes of St. Louis, where as a child, he seldom had food for breakfast, could afford few lunches and often only a meager dinner.

As he explained in his autobiography, Gregory became a jokester early on, telling jokes about himself first, then about others to get them th laugh with him, rather than tease him about his ragged clothes and lack of social graces.

He joined his high school track team initially so that he could take showers every day. Eventually, his speed gained him notoriety, respect and a ticket out of the ghetto. In 1951, he ran the second fastest mile for a high schooler; two years later, as captain of Southern Illinois University's track team he became the school's athlete of the year.

Later, armed with the confidence and encouragement he had acquired from sports, together with several successes during the start of his nighclub career, Dick Gregory, once the noted athlete, became the noted entertainer.

"I am motivated today out of a sense of gratitude, knowing how I made it as a black star," Gregory said.

As he developed his skill as a comedian, branching out into the political satire that has become a trademark, Gregory's material became more radical and topical as he dug "into a system, I was beginning to understand better and attack more intelligently."

Nat Hentoff, critic for the Village Voice and New Yorker magazine, says Gregory's performances during the late 60s rate him in the top three American political satirists of all time - along with Mort Sahl and Lenny Bruce.

"I will never forget when Gregory opened at the Blue Angel, a chic supper club no longer in existence," Hentoff said. "He broke in with the white audiences the way that no black entertainer ever could before.

"I'm oversimplying and the comparison is a little crude, but I would rank Lenny Bruce as the most creative, the most unpredictable of all political satirists, then Gregory and Sahl together," he said.

In the mid-'60s, something changed in Gregory, something he explains as "trying to find my spirituality." He became a vegetarian and a promoter of health food, proper diet and exercise. He also announced he would no longer pdrform in nightclubs because alcohol was served there.

"I had been giving college lectures and saying hew bad alcohol and drugs were. One day it dawned on me that how could I say all that was bad, then say "come down and catch my act at the club and have a taste?'" Gregory said.

Cutting out nightclub performances because clubs served alcohol did decrease his earning potential, Gregory admits.

"If the choice comes down to buying life insurance or going to a demonstration, damn thelife insurance," he said. "Someone is going to bury me when I die - I am more concerned about what is happening to my children and the world they live in while I am living.

"I hope that we can do even more in the future and I don't believe we have gone beyond the point of no return," Gregory said. "I plan to keep up the fight until it's over and there is nothing left to fight for. Hope lies in the future."