An angiogenesis inhibitor comprising a cysteine protease inhibitory compound. As the preferable cysteine protease inhibitory compound, epoxysuccinic acid compounds, peptide halohydrazide compounds, calpain inhibitory compounds, compounds of the formula (I) ##STR1## and compounds of the formula (VI) ##STR2## can be used. The angiogenesis inhibitor of the present invention suppresses new formation of blood vessels in the living tissues, so that it can be used as a superior therapeutic or prophylactic agent of angiogenesis associated with wound healing, inflammation, growth of tumor and the like; and angiogenesis as seen in diabetic retinopathy, prematurity retinopathy, retinal venous occlusion, senile discoid macular degeneration and the like, as well as for prevention of metastasis of tumors.