NEW YORK (AP) _ The ghosts of 1968 may still flutter around Columbia University, but a new generation of student protest leaders isn't haunted by the memories.

The students, who are protesting the university's investments in companies doing business in South Africa, were toddlers in April 1968, when an older generation of activists took over the building now blockaded by demonstrators.

The new demonstrators don't remember the earlier protest, which was marked by vandalism and violence. But they have heard the stories, and insist that they have learned much from their elders' mistakes.

''I can't impress upon you enough that this is 1985 and not 1968,'' said one of the protest leaders, Rob Jones.

The demonstration at Columbia began last Thursday when students from the Coalition for a Free South Africa barricaded the front doors to Hamilton Hall with chains and padlocks, posted themselves on the front steps and issued an ultimatum.

The protesters said they wouldn't move until they were arrested or the university agreed to rid itself - in three years - of its financial ties to South Africa. University President Michael Sovern stood by the university's policies and ordered the students to leave. They stayed.

At the request of the Columbia administration, a state Supreme Court judge scheduled a hearing today on a temporary restraining order requiring the students to leave Hamilton Hall. If police are sent in, the students have promised to face arrest peacefully.

It was a different atmosphere in 1968, when students took over Hamilton Hall and four other buildings to protest the planned construction of a gymnasium in a nearby Harlem park and the university's work in defense-related research. The protest began defiantly and ended violently, when police arrived with billy clubs to end the week-long occupation.

''I think a lot of people in the '60s hated things, and we don't,'' said David Goldiner, 20, one of six students who fasted for 15 days until Sovern agreed to meet with them Monday to discuss the South African issue.

''When the cops come, I think you're going to see people just walking away,'' Goldiner said. ''They aren't going to be shouting, 'Pigs 3/8'''

Goldiner, who remembers being wheeled to Vietnam War demonstrations in a stroller, said he disagrees with the image of college students today as apolitical careerists.

''Sure kids are concerned about their careers,'' he said. ''But when there's an issue like this, I think it shows that people can put all that behind them.''

Anthropology professor Alexander Alland Jr., who supported the student demonstrators in 1968 and supports the latest protest, believes it may reflect ''a slight groundswell'' of political activism returning to college campuses.

He said the current protests bear more similarity to the civil rights movement of the early 1960s than to protests in the late '60s, when there were selfish reasons for draft-age students to oppose the war in Vietnam.

''I think we've grown up a lot since '68,'' Alland said. ''I think the students have a very real sense of both morality on the one hand and realpolitik on the other. And I think that's very healthy.''