In this paper, the effect of papain on the tenderness of Bos grunniens meat was studied by analysis of the sensory qualities, changes of shear stress, diameters of myofibrillae and pH value after treated. The best processing conditions were achieved through orthogonal experiment and the best dosage of papain injected to the meat, temperature, enzymatic treatment time and the cooling temperature after the enzymatic treatment were 24000 U/kg, 20 ℃, 30 min and 5 ℃, respectively. The results showed that the sensory qualities were well, the shear stress depressed remarkably with prolong of storing time of Bos Gruniens meat, the diameters of myofibril were thin but the pH value were steady.