The father of Li Tianyi, 17, holds a rank equivalent to a general as dean of the music department for the Chinese army's Academy of Arts while his mother is a prominent singer.
The case is the latest allegation against the privileged children of officials to provoke anger.
Four of the five accused pleaded guilty at the Haidian district court, the official Xinhua news agency reported Friday after the two-day trial ended on Thursday.
It did not make clear how Li had pleaded. But during the hearings the Beijing News reported that he "did not admit to the sexual assault and did not admit to a relationship, saying he was drunk and did not know anything" about what happened.
The trial was closed to the public due to the ages of the accused.
Li's family has previously argued the incident was a case of prostitution rather than rape, according to reports.
Xinhua quoted the victim's lawyer as saying that she had been hospitalised because of stress and would not take part in the hearings.
Elite youths in China are commonly perceived to live extravagantly or above the law due to their connections, and the case dominated discussion in the country's hugely popular Internet chatrooms.
Following reported remarks by Li's family that the alleged victim may have been a bar hostess, a top legal expert inflamed controversy when he said the woman's profession made the act of gang-rape less harmful.
"Even if it was rape, the harm of raping a bar hostess is less than raping a woman from a good family," Yi Yanyou, a law professor at the prestigious Tsinghua University in Beijing, said on Sina Weibo.
Li Tianyi previously triggered controversy in 2011 after he and another teenager, both driving expensive cars, attacked a couple who reportedly blocked their passage, while the victims' child looked on.
In another scandal involving the offspring of China's wealthy elite, the son of a police chief in 2010 tried to use his father's status to avoid any consequences for a fatal car accident.
After running over a student in the northern province of Hebei, Li Qiming -- who is not related -- shouted: "Sue me if you dare. My father is Li Gang!"
He was later sentenced to six years in prison.