Objective To study the relationship between mutation of protein kinase (PK) genes and cancer occurrence. Methods In this study, the frequency of sequence alteration and gene expression variation of 514 PK genes in different types of cancers were obtained by searching the databases of cancer genomes. Results Results of gene expression search indicated that most of the PK genes have overexpression. Results of gene alteration search indicated that 512 genes have mutations; among which the frequency of amplification is higher than mutation and deletion, and deletion has the lowest frequency. The highest alteration frequency is 90%. Mutation frequency of 12 genes is higher than 30%, and 8 of them are associated with cancer occurrence according to the functional studies from bibliographic databases. Conclusions We suggest that PK genes with high mutation frequency might have vital functions, and they could be oncogenes or tumor suppressor genes. This study will shed light on our understanding of the function of PK genes (especially those members without functional studies) and their roles in cancer occurrence.