To study the risk factors of primary hepatocellular cancer (PHC) and their interactions, a case-control study with calculated odds ratios(OR) and synergy effects index(SI) was conducted. The history of hepatitis B, family histories of cancers and psychosocial factors were main risk factors of PHC, and their effects were positive and synergic. The SI between hepatitis B and family histories of cancers, psychosocial factors are 1.65 and 1.16 respectively.