The weekend "Compton Cookout" held off-campus was offensive and a "blatant disregard of our campus values," Marye Anne Fox said in a statement e-mailed this week to staff and 29,000 students.
"We reject acts of discrimination ... and we will confront and appropriately respond to such acts," Fox said.
A Facebook posting advertising the party invited people to a condominium complex off-campus "in hopes of showing respect" during Black History Month, according to a copy posted on the Web site for San Diego TV station 10News.
The posting offered a dress code heavy on T-shirts, rapper-style urban clothing by makers such as FUBU, and gold chains. Women were urged to go as "ghetto chicks." The invitation said such items as watermelon and cheap beer would be served.
The party theme disgusted some students on campus, where blacks comprise less than 2 percent of the undergraduate class.
"These are the people I go to school with, and knowing that they're mocking my culture and the history of black people is really offensive," sophomore Elize Diop said.
UCSD's vice chancellor for student affairs Penny Rue said administrators have identified nine partygoers and hope to decide within the next few weeks whether the students involved will be disciplined.
Rue said it's too early to say whether student conduct codes have been violated, but many policies don't apply to an off-campus event that was not sanctioned or organized by a specific student organization.
The party was organized by members of several UCSD fraternities, according to an e-mail from Gary Ratcliff, assistant vice chancellor for student life, that was obtained by the San Diego Union-Tribune.
A call to the university's Intrafraternity Council, which oversees campus Greek fraternities, was not immediately returned Wednesday.
The local chapter of Pi Kappa Alpha was the only fraternity identified in Ratcliff's e-mail.
In an e-mail Wednesday, chapter President Garron Engstrom said the event was not endorsed by the fraternity and violated its code of conduct. Those involved will be disciplined, he added.
"The fraternity regrets the display of ignorance and error-of-judgment made by any individual members who may have attended or were associated via social-media with the racially-offensive party," Engstrom wrote.