Abstract: Soybean-based adhesives with good rheological behaviors and curing properties were made of soybean flour by synergistic modification of aqueous polyamide and isocyanate. The effect of various modifiers on the rheological behaviors was investigated by using rotational rheometer. The results showed that the soy-based adhesives were pseudoplastic fluid, and the rheological behavior was better when 10% aqueous polyamide was added, but the isocyanate cross-linking agent had no influence on the rheological behavior of these adhesives at room temperature. Through the dynamic temperature scan mode of the rheometer test, it was found that the amount of isocyanate had great influence on the storage modulus and loss modulus of soybean adhesive. The bonding strength was 0.74 MPa and meeting the national board Ⅱ requirements(≥ 0.70 MPa) when 10% aqueous polyamide and 4% isocyanate were added simultaneously, which indicated that the cross-linking reaction happened between the aqueous polyamide/isocyanate synergistic cross-linking system and soy protein molecules.