About 100 black South African women have come to this world conference on women at great risk. With faces tired and sad but voices powerful, they have sparked deep emotion and support from other women around the world with their testimonies of life under apartheid.

At an international leaders seminar workshop sponsored by the National Council of Negro Women, five South African women told of their lives in vivid detail. "The homelands are tribal death cells," said one. "The lands are not fertile and there are only hungry women and children with no health facilities to speak of."

A South African nun was critical of her country's use of religion to control the population. "The Christianity of the colonial oppressors has dehumanized and destroyed our people," she said. "We need a structural change in South Africa."

Said another: "We are not citizens in our own country. We see our husbands only two weeks a year and the homelands are like concentration camps."

The audiences for the South African women, including women from Asia and Europe as well as continental Africa and the United States, have been responsive and lively.

At one forum, women from several different continents leaped to their feet to declare emotionally their solidarity with the liberation struggle when the South Africans finished their testimony. Some participants at the conference of nongovernment organizations supported economic sanctions and an arms embargo against South Africa.

In one audience, a South African woman told NCNW President Dorothy Height that a women's organization that Height had addressed in South Africa eight years before had been banned three weeks after she left the country. "And after they had splashed my visit on the front pages," Height replied indignantly.

So moved was civil rights leader Coretta Scott King by the vivid tales the women told of life under apartheid that she offered to host a conference in Atlanta next year on the subject of women and apartheid. And some American feminists and political activists have suggested that ending apartheid be added to the conference themes of "peace, equality and development."

The South African women have come with the hope that the nonofficial forum will press their case before the official United Nations Women's Conference that is also under way here. The South Africans are optimistic that many official delegates will be sympathetic to their cause.

The official U.S. delegation led by Maureen Reagan has only reluctantly agreed even to talk about apartheid, and then provided that the discussions "reflect unique concerns of women." The U.S. government supports a policy of "constructive engagement" with South Africa.

By contrast, the unofficial delegates, from feminists Betty Friedan and Bella Abzug to Coretta Scott King and Betty Shabazz (the widow of Malcolm X), have been strong advocates of an antiapartheid resolution coming out of this conference.

Solidarity with the women from South Africa was also pledged without hesitation at a forum entitled "Women Under Apartheid" and at an international leaders seminar sponsored by the National Council of Negro Women. "The time has come for women to speak out on what is happening to families under apartheid," said NCNW President Height. "But women's issues can't be separated from political issues."

Forum '85, the formal name of the unofficial conference, should press for an antiapartheid resolution, since any discussion of women's equality and development becomes empty words in a racist and sexist regime like South Africa's. Such a stand would also be in keeping with the freewheeling, independent nature of the nonofficial forum. Meanwhile, a reminder of how volatile the South African situation remains was given by one member of the delegation when an American woman asked if the delegation had experienced difficulty in leaving the country to attend the conference.

"There is no problem about leaving," came the reply. "That is part of the window dressing. The problem always is what happens when you get home."