Toward the end of Lou Ye’s “Summer Palace,” Yu Hong (Lei Hao) reflects that her college years were the “most confused” time in her life. A lot of us might feel similarly, but Yu Hong, the beautiful and passionate heroine of this beautiful and passionate film, is something of a special case.

As a young woman, freshly arrived at Beijing University from a provincial town, she shows a romantic, sometimes reckless appetite for experience, confiding in her diary a longing to live with maximum intensity. She satisfies this desire, in the movie’s heady, headlong first half, through a series of friendships and flirtations, most of all her fierce, jealous on-and-off relationship with Zhou Wei (Xiaodong Guo), a skinny, brooding intellectual and the love of her life.

But Yu Hong and Zhou Wei — and the various other friends, rivals and hookups who round out Mr. Lou’s portrait — are hardly ordinary university students. Or if they are, their matriculation comes at an extraordinary moment. Yu Hong arrives in Beijing in 1988, and her first year at the university, already full of emotional and sexual upheaval, ends with the pro-democracy demonstrations in Tiananmen Square and their violent suppression by the Chinese government.

“Summer Palace,” which was first shown in competition at the 2006 Cannes Film Festival, is remarkable for its candor about politics and sex. Perhaps unsurprisingly, its honesty has not been appreciated by Chinese authorities, who banned Mr. Lou from making movies for five years after he brought it to Cannes without their permission. But the film’s ardent, unsentimental embrace of youthful idealism is likely to strike a chord with anyone who can recall — or imagine — such feelings overtaking his or her own life.

Mr. Lou, however, is not interested only in reconstructing a vanished moment of high, intoxicating promise in his heroine’s (and his generation’s) youth. He is equally concerned with what comes after, with the drift, disappointment and compromise that seem, for his characters, to constitute both the legacy of Tiananmen and the mundane facts of postgraduate life. He follows Yu Hong and Zhou Wei as they make their way across the splintered landscape of adulthood, and takes note, via television clips, of the changing world around them.

Zhou Wei joins some of their university friends who have become expatriates in Berlin, while Yu Hong finds an office job in a provincial Chinese city. Fashions change. Rickety bicycles and battered envelopes give way to S.U.V.’s and e-mail. There are love affairs, a suicide, an abortion, and in the midst of it all Yu Hong clings to a belief in her own future that is all the more poignant for being somewhat vague.

Neither the later disaffection nor the earlier ardor feels in the least bit melodramatic or overstated. And in spite of its 2-hour-20-minute length, “Summer Palace” moves with the swiftness and syncopation of a pop song. Like Jean-Luc Godard in the 1960s, Mr. Lou favors breathless tracking shots and snappy jump cuts, and like Mr. Godard’s, his camera is magnetized by female beauty. But Ms. Lei, a tough and uninhibited actress, is not simply the object of the film’s gaze; Yu Hong’s resilience and vulnerability are the film’s emotional core, and its feverish rhythms follow the chaotic pattern of her desires.

In mapping the zone in which eros intersects with politics, Mr. Lou shows some affinity with Jia Zhang-ke, another frequently embattled Chinese director (whose new film, “Still Life,” also opens in New York today). “Summer Palace” can be seen as a companion piece, or even a sort of sequel, to Mr. Jia’s “Platform,” which followed a group of Chinese young people through an earlier period of cultural and social transition, from the early 1970s into the 1980s. But Mr. Lou, whose earlier films include the noirish “Souzhou River” and the moody period thriller “Purple Butterfly,” is temperamentally less of a realist than Mr. Jia.

The delirious scenes of dorm-room sex and nightclub dancing in “Summer Palace” convey more sensation than narrative or psychological meaning. And this is clearly the point. In the end Mr. Lou is not trying to reflect on the recent Chinese past so much as he is trying to communicate its texture. Perhaps inevitably, this effort leaves some loose ends and blurred impressions.

But in “Summer Palace” he nonetheless succeeds in finding a cinematic language that does more than summarize the important events of a confusing decade. He distills the inner confusion — the swirl of moods, whims and needs — that is the lived and living essence of history.

SUMMER PALACE

Opens on Friday in Manhattan.

Directed by Lou Ye; written (in Mandarin and German, with English subtitles) by Mr. Lou, Feng Mei and Ma Yingli; director of photography, Qing Hua; edited by Mr. Lou and Jian Zeng; music by Peyman Yazdanian; production designer, Weixin Liu; produced by Sylvain Bursztein, Li Fang, Mr. Lou and An Nai; released by Palm Pictures. At the Cinema Village, 22 East 12th Street, Greenwich Village. Running time: 2 hours 20 minutes. This film is not rated.

WITH: Xiaodong Guo (Zhou Wei), Lei Hao (Yu Hong), Xueyun Bai (Wang Bo), Lin Cui (Xiao Jun), Long Duan (Tang Caoshi) and Ling Hu (Li Ti).