Abstract: Although starch is widely used in industry, starch-based food is usually energy-intensive and prone to lack of protein and can rapidly increase blood sugar after meal. Therefore, protein is often used in combination with starch to prepare nutritionally balanced, low GI foods. Therefore, this study screened two plant proteins, black bean protein and lentil protein. Through evaluating their effects on some processing characteristics of wheat starch, proteins suitable for adding into starch-based foods were selected. To explore the effects of black beans protein and lentils protein on the physicochemical properties of wheat starch, different concentrations of black beans and lentils protein were mixed with wheat starch. The parameters, including size, pasting, aging, freeze-thaw stability, quality and structure and the change of microstructure were determined. The results showed that the addition of black bean protein and lentil protein could increase the grain size of wheat starch-protein conjugate, and the D₁₀,D₅₀ and D₉₀ of wheat starch-protein conjugate tended to increase. Combined with confocal laser images, the two proteins were observed to fill the gap or cover the surface of starch particles, indicating that the two proteins could interact with wheat starch. In the study of the thermodynamic properties of wheat starch, the addition of black bean protein and lentil bean protein could significantly increase the initial temperature T_o and the transition termination temperature T_c of starch, and decrease the gelatinization enthalpy, indicating that the addition of two kinds of proteins made wheat starch less gelatinized. Black bean protein could inhibit the regeneration of wheat starch, while lentil egg could promote the regeneration of wheat starch, and the aging degree of wheat starch could be reduced from 11.87% to 2.59% when the addition of black bean protein was 20%. When the addition concentration of lentil protein reached 40%, the retrogradation enthalpy value decreased and the promoting retrogradation effect weakened, indicating that different levels of the same protein had different effects on the retrogradation properties of starch. Both proteins could significantly improve the freeze-thaw stability of wheat starch. When the concentration of black bean protein was 40%, the water extraction rate of wheat starch decreased from 60.24% to 49.13%. The two proteins could increase the hardness of wheat starch gel, black bean protein had no significant effect on its elasticity, while lentil protein significantly increased the elasticity of wheat starch. Adhesion and adhesiveness were also significantly increased with the addition of the two proteins. These results indicated that the two proteins increased the cross-linking of wheat starch molecules and enhanced its network structure. Therefore, both proteins could improve the freeze-thaw stability of starch and inhibit starch gelatinization, and the degree of influence was related to the concentration of protein. Black bean protein could significantly inhibit starch retrogradation, while lentil protein exerted an opposite effect.