Crude polysaccharides were extracted from the whole plant of Botrychium ternatum （Thunb.） Sw. by using water extraction and ethanol precipitation method， and their inhibition effects on bacteria and proliferation of tumor cells were analyzed. The results show that the yield of crude polysaccharides from the whole plant of B. ternatum is 7.05%， and polysaccharides content in crude polysaccharides is 20.60%. Crude polysaccharides from B. ternatum show a certain inhibition effect on Escherichia coli and Staphyloccocus aureus， and that on E. coli is stronger than that on S. aureus， and the minimum inhibitory concentration is 0.206 and 0.309 mg·mL^-1， respectively； crude polysaccharides from B. ternatum also show an inhibition effect on proliferation of A-549 and Hela cells， and that on proliferation of Hela cell is stronger than that on A-549 cell， the semi-inhibitory concentration is 138.90 and 109.23 μg·mL^-1， respectively. Inhibition effects of crude polysaccharides from B. ternatum on bacteria and proliferation of tumor cells are all evidently smaller than those of several positive control， but show a tendency to gradually increase with the increase of mass concentration， and a certain concentration dependence.