SAN FRANCISCO (AP) _ Philippine President Corazon Aquino planned to talk to students during the last day of a U.S. visit in which she told the U.N. General Assembly her government had freed Filipinos from oppression and corruption.

Mrs. Aquino arrived Monday night at San Francisco International Airport aboard Air Force Two and was taken amid tight security to the downtown Fairmont Hotel. Today, she was to appear at the University of California at Berkeley, an elementary school, a City Hall reception and a banquet at the Moscone Center.

In her address Monday to the General Assembly, Mrs. Aquino did not mention former President Ferdinand E. Marcos or his wife Imelda, by name, but spoke of Marcos' 20-year rule of the Philippines with ''guns, goons and gold.''

She received a standing ovation and there were shouts of ''Cory 3/8 Cory 3/8'' as she rose to address the 159-member assembly.

She noted that Mrs. Marcos addressed the assembly's 40th anniversary session last year and said: The ''leader's wife came to this podium piously to call for a new human order - this when thousands of Filipinos were political prisoners.''

Mrs. Marcos wore a long, orange gown when she spoke to the assembly, but Mrs. Aquino was dressed in a simple beige suit and maroon blouse.

The president said ordinary people all over the world had advocated Marcos' removal, but added, ''Like so many leaders before me, I am obliged to say that we did this by ourselves.''

''The United Nations would lose purpose if it judged one system against another,'' she said. ''Yet, if the United Nations does not notice how governments treat people, it is nothing.''

She said that since ousting Marcos in February, her government had ''restored human rights and liberated our people from the oppression and corruption'' of the Marcos era.

''In the end, human values cannot be held down,'' she said. ''They couldn't be in Argentina. They couldn't be in the Philippines. They won't be in South Africa.''

Mrs. Aquino compared Nelson Mandela, the black nationalist leader jailed in South Africa, with her husband, former Sen. Benigno Aquino. He was imprisoned by Marcos' government and then assassinated when he returned to Manila from self-exile in the United States in August 1983.

The assassination brought anti-government demonstrations that culminated with the military-civilian revolt that led to Marcos' ouster last February. He is living in exile in Hawaii.

Since Mrs. Aquino's nine-day visit began here with a brief arrival ceremony Sept. 15, she has been received at the White House and Congress, and visited New York City and the Boston area, which was her home in exile.