Abstract: The objective of the study is to analyze the effects of different temperature,p H,Ca2 +,casein and chelating agent on the thermal stability of fresh mare's milk,using heat coagulation time method( HCT).The results showed that when the temperature and concentration of Ca2 +increased,the thermal stability of fresh mare's milk was degraded to varying degrees. Increasing the concentration of disodium hydrogen phosphate resulted in varying degrees of increasing of the thermal stability of fresh mare's milk. The thermal stability were significantly influenced by p H,trisodium citrate and casein,but was not significantly influenced by sodium dihydrogen phosphate.Through the quadratic regression rotation composition design,the optimized combined range were p H of 6.71⁶.83,the concentration of trisodium citrate of 0.34 ⁰.44 g / L,the concentration of casein of 3.29 ³.68 g / L.The results of the study could provide reference for mare's milk processing enterprises to ensure good quality of mare's milk products.