In the 1990s, Cheng also starred in a number of radio dramas.
His first film was Girls Without Tomorrow 1992 (1992) and at the time he was still called by the name Dior Cheng. He changed his name to "Ekin" before his break-out role in the Young and Dangerous series as Chan Ho-nam. The film was first meant to glorify the triad life, but after about the third film, the story focused more on the characters and explored the truth about the Hong Kong triads. It became so popular that it launched Cheng and co-star Jordan Chan to superstar status. And because of its incredible success, it is said to have made many youngsters at that time fond of the triad life, thus making teens throughout Asia join the triads. It also started a trend for triad films around that time and is considered to be a classic. The film led to six sequels, all starring Cheng, and a lucrative working partnership with Director Andrew Lau. Together they went on to make The Storm Riders, which was the highest-grossing Hong Kong movie at the time and the first film to use a truly large number of special effects. They also worked together on The Legend of Speed, a film about a street racer who would follow his father's footsteps of becoming a racing god, A Man Called Hero a movie adaption of the famous comic, about a martial arts master in America The Duel starring Cheng, Andy Lau, and a few other famous stars, and the comedy Women From Mars. In 2001, he acted in a movie titled Born to be King. This is the last instalment of a triad movie series Young & Dangerous.
Throughout his career Cheng has been featured in many magazines, and photo books, including an autobiography in Yes Idol Magazine (1997).
Cheng had a successful music career with BMG. But in the 2000s, he signed with EEG, a juggernaut company owned by Albert Yeung. Under this company he was 'frozen' and not allowed to put out any records. But as is a custom with EEG, he made several movies with other EEG stars. As of 2004, his contract with EEG ended and he returned to BMG briefly where he released a new record before signing with BMA. As of 2009, Cheng has once again returned as an Artist of Sony BMG. Through the course of his career, he has made several hits. Though many criticise Cheng for not having a voice capable of singing harder or higher-noted songs. And though his music career has been going smoothly, his most-acclaimed music came during the Young and Dangerous age. The theme song for Young and Dangerous 1 "Age of Friendship" is considered his best. Though he and Jordan Chan both sing a separate version, it was Cheng who sang it first.
In 2002 Cheng was asked to be the official Ocean Environment Ambassador. The Chief Secretary of HKSAR, Anthony Tsang presented the appointment letter. At the same press conference WWF also asked Cheng to be their Ambassador with a special interest in the marine environment. In this capacity he travelled to WWF's Whale Shark conservation site in 2007. TVB's Jade Channel aired the documentary.
Recently, Cheng returned to the movie scene (having taken a break in 2005 to work on the Ultraman TV series in Thailand). He had a brief appearance in My Name is Fame as himself. Soon after that he starred in Heavenly Mission, a triad/cop thriller starring alongside Stephen Fung and Alex Fong (this is not the Swimmer Alex Fong.). He has completed a Pang Brothers film called The Forest of Death, which was released in March 2007. His serial filmed in Mainland China based on the life of martial arts master Huo Yuanjia with former Young & Dangerous co-star Jordan Chan is currently in syndication. Current projects include a sequel to The Storm Riders, also directed by Pang Brothers and Kamui Gaiden being filmed in Japan. Cheng's latest film with Shawn Yue, Rule No. 1 directed by Kelvin Tong, won Best Actor Awards for both Cheng and Yue.
2006 saw the publication of Cheng's first book, 'Looking into Ekin's Eyes'. This book was very successful and is now in its third edition. In 2007 a Japanese version of the book was published.
Cheng has been asked by numerous companies to endorse their products. The most notable are Canon IXUS, Seiko, Shiseido JS and HTC. In 2008, Kingsoft featured Cheng in their popular online game The First Myth 2 (封神榜II) as "Er Lang Shen" (二郎神) a character in the game.
In 2007, Cheng made a guest appearance at a Leo Ku concert and received popular applause from the audience. He also represented Hong Kong in the 2009 Asia Song Festival, performing two songs. Since his last concert held 11 years ago, E-kin plans to hold his coming back concert during 18–19 December 2009 in Hong Kong.
