Abstract: In order to explore the interaction between starch and protein and the application of their composite, different ratios of octenyl succinic acid cassava starch ester (SSOS) and zein were mixed by reverse solvent precipitation method under different temperatures and different solid-liquid ratios.The physico chemical properties, such as water holding capacity, oil holding capacity, rheological properties and gelatinization properties were investigated.The results showed that the SSOS-zein composite gels were pseudoplastic fluid in the range of shear rates from 0.1 to 100 s^-1. In the range of 0.1-10 Hz, the storage modulus (G') and loss modulus (G″) of the composite gels increased with the increase of the frequency.When the mass ratio of SSOS to zein was 17:3, G'was the maximum and tanδ was the minimum.Different temperatures and different solid-liquid ratios exerted insignificant effect on the properties of the SSOS-zein complex. With the increase of zein ratio, the average particle size, protein content in the composite increased, oil holding showed an increasing trend, swelling properties and water holding showed a decreasing trend, emulsibility and emulsionstability increased firstly and then decreased, gelatinization temperature increased and setback decreased. The apparent viscosity of the composite decreased with the increase of shear rate in the range of 0-100 s^-1. The hardness of SSOS-zein composite gel increased firstly and then decreased with the increase of zein addition. When the SSOS-zein ratio was 19:1, the hardness of the composite gel was significantly higher than that of the SSOS starch gel. The adhesiveness of the composite gel was the biggest when the SSOS-zein mass ratio was 17:3.When the ratio of SSOS-zein was 17:3, the gel elasticity of the composite was greater than that of SSOS. The peak viscosity, trough viscosity, final viscosity and setback of SSOS-zein composite decreased with the increase of zein. The gelatinization temperature T₀ showed an increasing trend with the increase of zein level, indicating that the gelatinization of SSOS-zein composite became difficult.