Abstract: Objective 　To investigate the relationships between the expression of NET-1 protein and the microvessel density in ast rocytomas. Methods 　The expression of NET-1 protein and MVD marked with CD34 in 65 ast rocytomas was examined by immunohist rochemistry SP method. The association between them and the relationship with pathologic classification were studied. Results 　MVD was correlated with pathologic classification. MVD in NET-1 positive group was higher than it in the negative group. The expression of NET-1 protein and MVD was highly correlated ( rs = 0. 6682, P <0. 05) . Conclusion 　MVD maybe used as an indicator of determining malignant degree in ast rocytomas. NET-1 might promote the forming of microvessel density in ast rocytomas.