SAN FRANCISCO, JUNE 4 (MONDAY) -- South Korean President Roh Tae Woo arrived here Sunday from Seoul for what he said will be an important discussion with Mikhail Gorbachev during the Soviet president's one-day visit today to northern California.

Former secretary of state George P. Shultz, who was among dignitaries greeting Roh on arrival, described the expected meeting as "potentially a great event."

But as of late Sunday, the Soviets had offered no details on when or even if Gorbachev would work a discussion with Roh into his already hectic local schedule.

Gorbachev and his party arrived at 1:25 a.m. EDT and were whisked to the Soviet consul's office here, where about 400 demonstrators had assembled earlier, chanting for Lithuanian independence and an end to alleged human rights abuses.

Confusion about plans for a Roh-Gorbachev meeting, which the South Korean Embassy was heralding as a "summit" even as the Soviets were declining to acknowledge that it would take place, has capped a week of frantic and sometimes bewildered efforts to keep up with the changing plans of the Soviet president and his wife.

San Francisco is a city accustomed to celebrated tourists, including the kind who ride with motorcycle escorts, but preparations for this visit have left even some of the veterans looking slightly more harried than usual. They must cope with 22 hours of demonstrations, security barricades, traffic tie-ups and access-hungry reporters from all over the world.

"We all looked at each other and said, 'Geez, this freight train is coming at us,' " said Art Silverman, a spokesman for Mayor Art Agnos, recalling a meeting two weeks ago among city officials confronted on exceedingly short notice with the prospect of a friendly visit by the first Soviet leader to visit California since Nikita Khrushchev in 1959.

Silverman telephoned for advice to a firm that handled press and public relations for the visit in 1987 of Pope John Paul II and said the executive to whom he spoke was staggered by the sheer scope of what San Francisco was trying to do.

"She said, 'We spent almost a year doing this, and you only have 13 days,' " Silverman recalled. "And I said, 'That's the good news. The bad news is we don't have any budget.' "

A public relations firm called the PBN Co. took up the mayor's offer to put together a very large job for free, and it is through PBN's suddenly frenzied offices that approximately 2,000 reporters have been trying to keep straight details of the Gorbachev visit.

With a massive hammer and sickle draped down one wall of the firm's conference room, a tableful of facsimile machines have been transmitting international credentials requests and regular updates of the planned schedule, beginning with the Gorbachevs' breakfast at 9:15 a.m. PDT with former president Ronald Reagan and his wife at the Soviet consul general's residence.

After breakfast, the Gorbachevs are to be driven 45 minutes south to Stanford University, where for the last week students and faculty members have engaged in a gloves-off scramble for chances at an actual glimpse of the Soviet president and his wife.

A computer was used to conduct a lottery distribution of free reserved tickets to Gorbachev's speech at the campus's 1,700-seat Memorial Auditorium, setting off a brisk business in ticket-scalping.

Gorbachev has also been scheduled for a half-hour stop at the Stanford Business School for what the latest agendas describe as "informal dialogue" with a group of Stanford scholars.

Gorbachev is to return to San Francisco for a midafternoon luncheon at the Fairmont Hotel featuring elegant California food and an audience of San Francisco's business elite.

Before the Gorbachevs' planned 6:30 p.m. departure, their schedule appears to offer a few gaps in which a meeting with Roh could take place, but locals trying to keep up with the Soviets' plans are rapidly learning to take last-minute changes in stride.

At the Stanford-based Hoover Institution, officials in the midst of festive plans for Gorbachev's planned visit were told suddenly last Monday that the Soviets would not be coming there.

"I simply don't have an explanation," said Hoover Director John Raisian, who before last week had been told that the Soviet visitors were greatly interested in viewing the Hoover library's famous collection of original Russian materials.

Last Monday, after scores of press and television reports remarking on the notion of the world's most famous communist visiting one of the world's most famous bastions of conservative and anti-communist scholarship, Raisian was informed that the visit had been cancelled because of "time pressures."

Also left in confusion was Children's Hospital in Oakland, site of considerable excitement when Soviet consular staff members suggested that Raisa Gorbachev was interested in visiting a special cardiology program established to help Soviet physicians set up a children's cardiac center in Leningrad.

Hospital officials arranged for multiple telephone lines and sped the recarpeting job on the floor that she was expected to visit, but as of Sunday no word had been received as to when or if the Soviet First Lady would come. "The Hoover Institution called here yesterday," hospital spokeman Steve Tiger said, "to commiserate."

If Raisa Gorbachev does not make it to the hospital, no one who has seen her schedule will wonder at the omission. While her husband attends the Fairmont luncheon, she is due to be whisked through San Francisco on an ambitious 90-minute sightseeing tour that calls for stops at Golden Gate Park, Fisherman's Wharf, Bank of America headquarters and the Opera House, each of which is separated from the others by enough distance and traffic to daunt even the hardiest tourist.

Mrs. Gorbachev's original schedule called for a stop at San Francisco's Civic Center, the collection of municipal buildings near the symphony and opera house, but that was dropped because of what officials later said was an early misunderstanding.

The center's plaza has for many months served as a kind of massive campsite for many of the city's homeless, forming a continuing public reminder of one of Agnos's most pressing civic problems.

The apparent change in itinerary prompted barbed questions about whether Agnos had been disturbed at the idea of the Soviet president's wife contemplating the poverty outside the mayor's front door.

But Silverman said Agnos, who frequently discusses the homeless issue and has helped to arrange the opening of two new centers to aid the homeless, would have had no objection to including the civic center campout on Mrs. Gorbachev's tour.

"You can call it our own glasnost policy," Silverman said. "We have no desire to try to hide the problems of major cities in America. . . . The mayor has said on many occasions that he's wanted to keep these people in front of his window as a reminder of the existence of the homeless problem and the need to do something about it."