Kezman joins Butt at South China
Serb Kezman also played for Dutch club PSV Eindhoven, Turkey's Fenerbahce and Spanish side Atletico Madrid.
"Having played the majority of my career in Europe I wanted a new challenge in my life," Kezman told the website.
"The opportunity to play for South China FC excites me and I feel I can offer the team many things. I have maintained fitness over the winter and feel ready to play and score goals.