In this study, the effect of thermal modifications (25, 75, 85 and 95 ℃ for 15 min) on the structure and digestibility of milk protein concentrate (MPC70) was evaluated. Results shows that the free sulfhydryl content and surface hydrophobicity increased significantly with temperature up to 95 ℃, reaching the highest value of 42 μmol/L and 1 008, respectively. The contents of α-helix and β-turns decreased, while the contents of β-sheet and random coil increased. sodium dodecyl sulfate polyacrylamide gel electrophoresis after simulating gastrointestinal revealed that a certain degree of heat treatment enhanced the digestibility of milk proteins, which may be attributed to structural changes.