About 300 disabled persons - some led by seeing-eye dogs, others in wheelchairs and many "speaking" with their hands - staged a sit-in yesterday at the Department of Health, Education and Welfare to demand that civil rights regulations for the handicapped be signed and enfoced.

The protest in Washington conincided with similar demonstrations by thousands of disabled citizens at nine regional HEW offices in major cities across the country.

Dr. Frank Bowe, director of the American Coalition of Citizens with Disabilities, told a news conference on Capitol Hill that HEW Secretary Joseph A. Califano Jr. "has failed to fultill the promise of equal rights" for the handicapped by refusing to implement Section 504 of the 1973 Rehabilitation Act.

Section 504 affects the 36 million Americans who suffer some kind of disability and covers activities in about 16,000 school districts, 8,000 colleges and universities and hundreds of hospitals and other insitutions.

Some major corporations doing business with the federal government already have complained that the proposed regualtions would be too costly to implement.

The Kaiser Aluminum and Chemical Company, for example, estimated that it would cost $160,000 to make its headquarters in Oakland, Calif., barrier free.

However, Mainstream, a nonprofit organization created to help bring the handicapped into the mainstream of society, contends that the job could be done for as little as $8,000.

At the press conference, Bowe said that Califano has put off signing the proposed regulations so that he will have time to write weaker ones and build in "loopholes, waivers and exemptions."

But Califano, who stood on a coffee table outside his office, surrounded by demonstrators, told the group that he had not signed the 504 regulations because he wants time to "study and assess" the proposed rules.

"The previous administration took 2 1/2 years to produce a complex regualtion that it then refused to sign," he said. "I believe it is reasonable for me to take 2 1/2 months to examine those regulations so that I may understand them and assess their implications."

Califano, who spoke above the shouts of the crowd, said the regulations posed "difficult questions" such as whether an on-going drug addict or alcoholic is considered handicapped and is covered by 504 regulations. Currently, such persons do appear to be included among those who would benefit. Califano said he must decide whether they should be covered.

After Califano finished his 10-minute impromptu speech, Bowe, who is deaf, stood up and suggested to Califano that he sign the regulatios now and review the rules for possible changes later.

"I will do my best to be as fair as I can to act on your just and legitimate needs," said Califano, who stepped down from the coffee table and walked back into his office.

Califano, who had hurried back from a trip to Atlanta for a possible meeting with the group, told them he would sign revised 504 regulations by early next month.

In contrast to usual security at HEW, the big swinging doors were left open yesterday for easy access by those on crutches and in wheelchairs.

Outside HEW headquarters, about 200 persons marched in a circle, carrying placards and shoiting civil rights slogans reminiscent of the protests by blacks in the early 1960s.

Outside of Califano's office, the protesters at one point sang, "We Want 504" to the tune of "We Shall Overcome," a standard protest song of the black civil rights movement.

George Reed, 65, who is blind and operates a small gift shop at the Department of Agriculture, smiled broadly as he clutched a collapsible walking can and sang along.

"I marched for my civil rights as a black man in the '60s." he told a reporter. "I never thought I'd see this day come when handicapped people would rise up and demand their rights. We've been begging for a long time.Now we're demanding our rights."