Sammy Lau’s uncle is legendary Hong Kong film director and superstar Lau Kar-leung. At age of five Sammy followed his father Liu Chia-yung to Taiwan to make parts in movies. In 1996 Billy Lau help young actor to sign a contract with TVB.  Later, he decided to leave the TVB and made his acting career reach a new milestone. In addition to TV series, Liu Yongjian also performed in movies, such as "Taxi Judge" and "Speed ​​Zombie".