[1] Born in British Hong Kong to ethnic Chinese parents, Mok represented the Republic of China (Taiwan) and spending his whole professional career in the Hong Kong leagues.

Mok was with Yiu Cheuk Yin and Ho Cheng Yau one of the "Three Aces" that formed the strikeforce of South China Athletic Association in the 1950s and 1960s.

[2] He was part of the Republic of China (Taiwan) team that won the gold medals at the 1954 and 1958 Asian Games.

[4] Mok also represented Hong Kong Chinese[5][6] in a non-FIFA recognized match against Malayan Chinese in 1959 Ho Ho Cup;[7] in 1957, Mok also represented Hong Kong League XI in Merdeka Tournament, a friendly tournament; the team was almost entirely composed of the players of Eastern Sports Club, which was playing friendlies in the Asia-Pacific.

[9] Mok was also selected to the 1961 edition as a member of Hong Kong League XI.