Abstract: By measuring the p H value, moisture content, yield, texture and meltability of Cheddar cheese, the effect of different heat treatment processes of low-fat milk on quality was analyzed. The results indicated that the denaturation rates of whey protein in three different heat treatments were 17.5%, 35.1% and 63.8% respectively. As the heat treatment intensity increased, the p H value and meltability of Cheddar cheese decreased, whereas moisture content and yield increased.Besides, the texture index of hardness, elasticity, cohesiveness and chewiness decreased and the adhesion increased. In addition, the differences in quality of cheese were analyzed by scanning electron microscopy and electrophoresis.The results showed that with the increase of heat treatment intensity, the denaturation rate of whey protein increased, and the formed polymer was trapped in the network structure of cheese, which affected the aggregation of casein and then had an effect on its quality.