Abstract: 15 fractions were obtained from the venom of Agkistrodon acutus by column chromatography.Chemical principles of biological activity of crude venom and every fraction were examined the experimental results are as follows:1.Crude venom and each fraction contain argininie esterase,protein hydrolase,alkaline-phosphatase,phospho-biesterase,5 -phospho-biesterase,5-nucleotidase,adenosine diphosphatase,adenosine triphosphatase,L-amino-acid oxidase and phospho-esterase A,but choline-esterase and ribonuclease are not found.2.Protein hydrolase,5-nucleotidase and adenosine diphosphatease exist commonly in crude venom and each fraction.3.Arginine esterase exists in crude venom and the sixth-to thirteenth fractions but the highest activity appears in the eighte fraction.4.The first and the fifth to thirteenth fraction show higher blood cagulant activity.Crude venom,the first,the second and the ninth to the fifteenth fractions show bleeding toxin,The twelfth (the mortality is 2/5 on mice) and the thirteenth fractions (the mortality is 3/5 on mice) show higher toxicity.Crude venom,the first,the second and the ninth to the fifteenth fractions show fibrinolytic activity.