Jaycee Chan, 32, said he had "no reason, no excuse" for taking to drugs despite his father being a goodwill ambassador for China National Anti-Drug Committee in 2009, which promoted anti-drug education.
"After this correction by the justice system, I have changed my outlook on life and my values," said Jaycee.
Jaycee said his father did not intervene on his behalf and he received no special treatment in prison.
Two days after his release, a forlorn Jaycee bowed before he addressed the media today.
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His news conference was telecast by state-run CCTV to highlight the crackdown on drug abuse by rich in China.
Jaycee was born to Jackie and his wife, Taiwanese actress Lin Feng-Jiao. He was raised in Los Angeles and briefly attended college in Virginia but did not pursue his studies.
His father Jackie Chan, a Hong Kong-based film actor, enjoys a close rapport with China's leadership and currently is the member of the advisory legislature, the Chinese People's Political Consultative Conference (CPPCC).
After his son's arrest, a shocked Jackie flew to Beijing and apologised to public, lamenting his failures as a father.
Jaycee could have been sentenced for up to three years, but was shown leniency for admitting his mistake and for his assurance to not indulge in such behaviour again.
In the first half of the year, more than 7,800 people have been detained on drug charges in Beijing, an increase of about 72 per cent year-on-year, police said.
On Thursday, popular Chinese singer Yin Xiangjie was prosecuted in Beijing for possession of drugs. Yin, 45, was arrested in December and 13.93grams of crystal methamphetamine and 1.02 grams of marijuana were seized from him.
"Only 0.15 per cent of suspects are from the entertainment industry, while more than 93 per cent are unemployed," said a police statement.
"To pay attention to the celebrity drug crackdown can be helpful for the war on drugs, as drug user in China gains younger users," a Beijing-based university professor of public security told the official media.