No. of albums: 11 cantonese album and 4 mandarin albums

1985:
2nd Runner-up HK-TVB Talent Song Contest
First Debut Album - Imsonia

1989:
HK Hit Radio Best Newcomer 1st Rummer-up
HK Commercial Radio Best Newcomer 2nd Runner up

1991: 2nd Album titled "Don't Leave Me"

1992:
Signed to Cinepoly Records, subsidiary of Polygram Records
Participated as the character Raymong in file of Justice Drama Series and sang all theme songs for all five sets of series from 1992 to 1996.

1995: Released first debut Mandarin Album

1997:
Metro Radio Most Promising Male Single 1st Runner-up

William So was discovered in the 4th New Talent Contest organised by HK-TVB in 1985 of which William won second place and began his music career. William became a household name in Hong Kong through his participation in the Hong Kong version of L. A. Law drama series, namely File of Justice which lasted five sets of series throughout five years. William played an up and coming young lawyer in File of Justice. Of course, William's sleek appearance and sense of justice made William So a much admired character of the TV show.

Besides Hong Kong, William's soaring popularity can also be seen in Taiwan where William is known as "So Nice". His 3rd Mandarin Album sold more than 300,000 in Taiwan alone and the hit song "Men should not let Women Cry" scored 1st place in the Music Charts, Karaoke Charts and an entertainment survey recognizes that the song has more airplay in Karaokes and Radio Stations than any other songs.

William is known for his soul and jazz music. He has reputation as one of the best ballad singer along with Jacky Cheung, Emil Chau and Jeff Chang. Even in Malaysia, you could frequently find William's songs in music charts and sales.