Abstract: The activity and isozyme of endopeptidases during peanut seeds germination were detected to research the activity of endopeptidase affected by different temperatures and inhibitors of metalloprotease EDTA. In this study，we used the standing boards to germinate peanut seeds，used spectrophotometry to determine the activity of endopeptidase during the germination of seeds. It was found that the ativity of endopeptidase reached the maximum at the sixth day. Using SDS-PAGE gel electrophoresis，we found 5 kinds of endopeptidase isoenzymes， in which there were two kind of metalloprotease of the 6 days of germination，and 7 kinds of endopeptidase isoenzymes，which there were 4 kind of metalloprotease after 8 days and 10 days of germination. The optimum temperature of these endopeptidase isozymes was about 40℃. Gelatin electrophoresis results showed that EGTA had inhibitory effect on two isozymes of metal type at 6 days of germination，but it did not completely inhibit the activity.