Cancer is a class of complex diseases caused by gene-environment interaction. Risk for the development of cancer varies greatly among individuals with the same environmental exposure, indicating significant roles of genetic factors in carcinogenesis. Thus, the identification of such genetic factors has profound importance in understanding and clinical care including early detection, diagnose and treatment of cancers. Recently, genome-wide association study (GWAS) has been proved to be a powerful and successful tool for the discovery of genetic factors associated with complex phenotypes and diseases including cancer. GWAS in the US and some European countries have identified many genetic loci associated with a variety of common cancers. Since 2010, Chinese scientists have also published a series of high profile cancer GWAS, which contributed significant progresses in genetic etiology of common cancers in Chinese populations.