Abstract: Using LSAB immunohistochemical metheds, we examined the P53 and PCNA protein expression in 56 cases of astrocytic neoplasms. The results showed that there is a higher poitive rate in Ⅱ、 Ⅲ ~ Ⅳ class than Ⅰ class in astrocytic neoplasm. There is no obvious difference between Ⅱ and Ⅲ ~ Ⅳ calss. The results suggest that the expression of P53 and PCNA protein play an important role in estimaing the degree of malignance in astrocytic neoplasm.