Thermal treatment is a key procedure in dairy products preparation to ensure the products safety.During the heat processing,a variety of chemical reactions occurred,such as Maillard reaction,lactose isomerization and protein denaturation,which are all closely related to the heat treatment intensity.The objective of the present study is to evaluate the effect of different thermal treatments on the heat-sensitive components in milk by comparing the heat damage between raw milk,pasteurization milk,ultra-pasteurization milk and UHT milk.In the raw milk,the furosine contents increased with increased heat treatment strength,while plasmin activity decreased.The thermal treatment caused whey protein denaturaed,in which β-LgB and BSA were more sensitive to heat treatment and the α-La was heat resistance;the content of vitamin B1 and B2 decreased as the improvement of thermal treatment.We can determine the content or activity of the furosine,α-La and plasmin to be used as the heat indicators in order to identify different heat treatment of milk.This will help dairy products manufacturing and protect the interests of consumers.