LOS ANGELES, March 23— ''Titanic, '' the James Cameron epic about a tragic love affair aboard the doomed ocean liner, glided triumphantly through the 70th annual Academy Awards tonight, winning 11 accolades, including best picture and the top director Oscars for Mr. Cameron. The film's honors tied it with ''Ben-Hur'' for the most ever.
Also at the ceremony, the Academy of Motion Picture Arts and Sciences presented its top acting awards to Jack Nicholson and Helen Hunt for ''As Good as It Gets, '' and its supporting-acting Oscars to Kim Basinger for ''L.A. Confidential'' and Robin Williams for ''Good Will Hunting.'' It was Mr. Nicholson's third Academy Award.
The Oscar for best documentary went to ''The Long Way Home, '' a searing film about the hardships endured by liberated concentration camp inmates after World War II. Curtis Hanson and Brian Helgeland won an Oscar for their adaptation of the James Ellroy novel ''L.A. Confidential.''
The winners of the original screenplay award were Ben Affleck and Matt Damon for ''Good Will Hunting, '' in which the two actors also starred.
At the close of a long evening, Mr. Cameron accepted the best-picture award for ''Titanic'' and asked for a few moments of silence for those who died in the ocean tragedy. ''The only thing we truly own is today, '' he said. ''Life is precious.''
Ms. Hunt, the Emmy-Award winning star of NBC's ''Mad About You, '' received her best-actress Oscar for playing a world-weary waitress and single mother in James L. Brooks's comedy ''As Good as It Gets.'' The 34-year-old actress said emotionally, ''I'm here for one reason - that's Jim Brooks.''
Ms. Basinger, whose role as a sultry prostitute in ''L.A. Confidential'' marked a comeback for the 44-year-old actress, said excitedly after winning the supporting-actress award, ''If anybody has a dream out there, I'm living proof that it can happen.''
Mr. Williams, who had previously received three nominations for an Oscar but never won, seemed overwhelmed while accepting his supporting-actor award. ''This might be the one time I'm speechless, '' said the 46-year-old actor, who portrayed a psychologist in ''Good Will Hunting.''
Although Academy officials said beforehand that it was doubtful that Billy Crystal, the host of the show, would mention the current sexual allegations by several women against President Clinton, Mr. Crystal obviously thought otherwise.
''A year ago the White House was complaining there was too much sex in Hollywood, '' he said. ''Times change.'' At another point Mr. Crystal brought down the house when he said: ''There's a billion people watching the show tonight. Linda Tripp is taping it.''
Even before the awards presentation, the odds were heavily in favor of ''Titanic, '' the 3-hour-and-14-minute blockbuster that has been No. 1 at the box office for 14 weeks and has grossed a record $1.2 billion around the world, including $495 million in the United States. The film starred Leonardo DiCaprio and Kate Winslet as fictional lovers aboard the vessel that sank in the Atlantic in 1912, carrying more than 1, 500 people to their deaths.
The Oscar ceremonies took place at the 6, 000-seat Shrine Auditorium, in a bleak neighborhood in South-Central Los Angeles near the University of Southern California campus. Security was far more visible and intense than in previous years - even movie stars and nominees went through metal detectors - partly because of a yearlong labor dispute between ABC, the Disney-owned network that broadcast the show, and the National Association of Broadcast Employees and Technicians. Members of the union picketed near the Shrine's entrance as limousines pulled up and stars walked onto the sun-drenched red carpet.
The other Oscar nominated films were ''As Good As It Gets, '' ''L.A. Confidential, '' ''The Full Monty'' and ''Good Will Hunting.'' The Oscar winners were selected by the 5, 371 voting members of the Academy of Motion Picture Arts and Sciences.
With 14 Oscar nominations, which tied the record set by the Joseph L. Mankiewicz classic ''All About Eve'' (1950), ''Titanic'' was, from the outset, almost certain to dominate the Academy Awards. Mr. Cameron, who was pilloried in the press and across Hollywood last year for going $100 million over budget on his $200 million movie, is now perhaps Hollywood's premier filmmaker.
Mr. Cameron said recently that in creating ''Titanic, '' he felt audiences were eager to see a romantic and historic epic and were wearying of science-fiction films. ''We went in with a harebrained theory - let's do a romantic epic because no one's done one in a long time, '' the 44-year-old filmmaker said. ''We thought there was a hunger for emotion, for character, for drama.''
One of the highlights of the evening was a tribute to Stanley Donen, the choreographer-turned-director in the heyday of the studio system. Mr. Donen, who received an honorary Oscar, was co-director with Gene Kelly of ''Singin' in the Rain'' (1952), perhaps the greatest movie musical.
But the 73-year-old filmmaker's elegant style and use of color was also evident in such musicals as ''Seven Brides for Seven Brothers'' (1954) and ''Funny Face'' (1957), as well as nonmusicals like ''Indiscreet'' (1958), ''Charade'' (1963) and ''Two for the Road'' (1967). Mr. Donen performed an agile two-step and sang ''Heaven'' after picking up his Oscar from Martin Scorsese.
Another highlight was a historic gathering of old and new Hollywood. Among those invited to the ceremonies were more than 120 past Oscar winners, and about 70 showed up. Among those who appeared: Claire Trevor, 89, a winner for 1948's ''Key Largo''; Shelley Winters, 74, who won Oscars for ''The Diary of Anne Frank'' (1959) and ''A Patch of Blue'' (1965), and Luise Rainer, 88, who won for ''The Great Ziegfeld'' (1936) and ''The Good Earth'' (1937).
''It's amazing, '' remarked Ms. Winters as she stood on the red carpet entering the Shrine. The veteran actress wore glittering diamonds. ''From all my lovers, '' she said with a laugh.
Greg Kinnear, nominated for an Oscar for best supporting actor for his role in ''As Good as It Gets, '' summed up the mood of the other nominees (as well as many of those attending) the Oscar ceremonies. As movie stars surged into the Shrine, Mr. Kinnear said: ''This is bizarre. This is like an out-of-body experience.''
The 1998 Oscar Winners
Picture: ''Titanic''
Actor: Jack Nicholson, ''As Good as It Gets.''
Actress: Helen Hunt, ''As Good as It Gets''
Supporting Actor: Robin Williams, ''Good Will Hunting''
Supporting Actress: Kim Basinger, ''L.A. Confidential''
Director: James Cameron, ''Titanic''
Foreign Film: ''Character, '' the Netherlands
Original Screenplay: Ben Affleck and Matt Damon, ''Good Will Hunting''
Adapted Screenplay: Brian Helgeland and Curtis Hanson, ''L.A. Confidential''
Art Direction: ''Titanic''
Cinematography: ''Titanic''
Sound: ''Titanic''
Sound Effects Editing: ''Titanic''
Original Musical or Comedy Score: ''The Full Monty, '' Anne Dudley
Original Dramatic Score: ''Titanic, '' James Horner
Original Song: ''My Heart Will Go On'' from ''Titanic, '' James Horner and Will Jennings
Costume: ''Titanic''
Documentary Feature: ''The Long Way Home''
Documentary (short subject): ''A Story of Healing''
Film Editing: ''Titanic''
Makeup: ''Men in Black''
Animated Short Film: ''Geri's Game''
Live Action Short Film: ''Visas and Virtue''
Visual Effects: ''Titanic''
