Abstract: In the present study, a milk coagulating enzyme was extracted from kesinai (Streblus asper Lour) leaf with Tris-HCL buffer in Biotechnology Laboratory at University Putra Malaysia during the year 2003. The effects of extraction pH, coagulation temperature, CaCl2 and enzyme concentrations on the milk coagulating activities of kesinai leaf crude extract were evaluated. The maximum enzyme activity was observed at extraction pH 7.2 and 65°C. The presence of CaCl2 up to 6 mM decreased the milk clotting time. Higher salt concentrations, however, giving rise to harder coagulum-like gel. The milk coagulation activity was improved predominantly by increasing the volume of crude enzyme solutions up to 60 μL.