Abstract: Purpose and Methods : In order to investigate the p16 gene expression and it s relationship with pathological type and clinical stage , 52 Wilms tumor specimens and 7 normal renal tissues aroud tumor were stained routinely by SP immunohistochemical method. Results : Positive expression rate of p16 gene was 30. 8 % 16/ 52) in tumor specimens and significantly lower than that in cont rol 100 % (7/ 7) ( P < 0. 05) . The positiverates were 37. 2 % (16/ 43) , 0 % (0/ 9) in the favorable pathological type and the unfavorable pathological type ,and 47. 6 % (10/ 21) , 37. 5 % (3/ 8) , 28. 6 % (2/ 7) ,6. 3 % (1/ 16) in Ⅰ, Ⅱ, Ⅲ, Ⅳclinical stage respectively. Conclusion : The positive expression of p16 gene was correlated with pathological type and clinical stage , and p16 inactivation seems to be the later event of Wilms tumor progression.

Key words: Wilms tumor, p16 gene, gene expression