Abstract: Transglutaminase(TG) has the cross-linking characteristics. In order to increase fat content in beef muscle, appropriate method and content of TG addition were chosen and the artificial beef fat was injected into beef that fat did not deposit well under the condition that the stability of artificial beef fat and activity of enzyme were not affected. At the same time, the surface of beef was treated with TG, NaCl and polyphosphate, in order to bind the protein on the surface of beef and reduce the fat outflow. When 0.8% TG(of total emulsion) was put into beef fat after ripening before injecting and interval between adding TG and injecting fat was not longer than 1 h, a high fat binding rate was obtained. The three optimized factors were determined according to orthogonal experimental results as follows: TG 0.28%, NaCl 0.4% and Phosphate 0.09%.