The P53,Rb,nm23,C-berB-2 genes of testicular tissues were assayed with immunohistochemical method in 30 hereditary cryptorchids.The results indicate that nm23 of 4 cases and C-berB-2 of 2 cases were positively stained in 30 cases,and one of the 6 cases was both positively stained in an abdominal undescended testis.The findings suggest that aberrantion of nm23,C-berB-2 genes is associated with testicular neoplasms of retained testis,specifically abdominal undescended testis has trend to variation of correlative oncogenes of testicular tissues.