Objective To study the angiogenesis in serous ovarian neoplasms. Methods Immunohistochemical method was used to examine microvessei density (MVD) and the expressions of vascular endothelial growth factor (VEGF) in 76 cases of serous ovarian neoplasm. The relationship between MVD and VEGF were investigated. Results MVD in the tissues of cystadenoma, bordline cystadenoma and cystadenocarcinoma were 7.8±2.4, 17.5±3.3 and 27.6±7.5; VEGF expressions were (16.1±3.9)%, (36.7±14.2)%, (52.3±22.8)%; the differences were significant respectively. Of cystadenocarcinoma grade 1, grade 2 and grade 3, MVD were 18.3+3.4, 24.2±3.1, and 32.3±6.4, VEGF expressions were (30.9±16.2)%, (48.0±18.4) % and (62.1±21.3) %, the differences were significant respectively. Of FIGO stage Ⅲ～Ⅳ and stage Ⅰ～Ⅱ, MVD were 28.9±4.7 and 22.0±4.7, VEGF expressions were (55.1±22.9) % and (40.18±18.0) %, the differences were significant respectively. There was significant positive correlation between VEGF expression and MVD. Conclusion Angiogenesis is very important in the development of serous ovarian neoplasms.