Abstract: Taking cassava (Manihot esculenta) leaves as the raw material, the optimum extraction conditions and enzymatic properties of polyphenol oxidase (PPO) from cassava leaves were studied. The results showed that, the optimal extraction conditions were as follow, pH value of PBS was 6.6, solid-liquid ratio was 4 mL/g and extraction time was 6 h. The enzymatic reaction of PPO from cassava leaves showed that, the maximum absorption pick was at 399 nm. The Michaelis constant (Km) was 0.8 mol/L and the enzymatic kinetic equation was V =2000 S/0.8+S by using catechol as substrate. The optimal reaction temperature of PPO was 37益and optimal pH value of PPO was 7.0.