To evaluate in vitro digestion of milk fat in some commercial milk and dairy products, the distinctive digestion on lipase hydrolysis was investigated in 6 different conditions at 0, 20 and 40 ℃ for 15 and 30 minutes, respectively. The digestion remarkably was differentiated not only concentration of substances, passage of reactive time, optimal temperature but also other additive compositions which were factors of inhibitor, cofactor, sedimentation. These comparative investigations of specificity of enzyme were expected the educational effect on the undergraduate experimentation.