Objective:Vasohibin (VASH),one of new gene families,is believed to be involved in cancer-promoting. However,the exact function is still unknown. To analyze the expression level of nuclear VASH2 protein in human fetal tissues from different gestational ages. Methods:Immunofluorescent method (IF) was used to detect the expression of VASH2 protein in 293T and intracellular localization. Nuclear VASH2 polyclonal antibody was used to analyze the expression level of nuclear VASH2 protein in human fetal tissues from different gestational ages,and the change of embryonic cell mitotic counts and the expression of nuclear VASH2 was assessed by using immunohistochemistry (IHC). The cell growth was detected by methyl thiazolyl tetrazolium (MTT). Flow Cytometry (FCM) was used to determine the cell cycles. Results:We found that the protein expression of VASH2 (with 355 amino acid residues) was located in the cytoplasm while VASH2 (with 311 amino acid residues) was located in the nucleus. Nuclear VASH2 was generally lower in fully-developed embryos and markedly expression during undergoing several maturational processes. There is a significant positive correlation between nuclear VASH2 and mitotic counts (r = 0.826,P < 0.01). Nuclear VASH2 promoted proliferation of 293T cells. FCM analysis showed increasing proportion of S and G2 / M phase in nuclear VASH2 transfection. Conclusion:This is the first study to report differences in the intracellular localization of VASH2 protein. Nuclear VASH2 protein found in a variety of tissues is not a tissue-specific protein,and may play important roles in histogenesis and organogenesis.