The warpage of injection molded part is one of the most important criteria to validate the quality of plastic part. In order to increase the accuracy of warpage prediction,the tensile loading-unloading tests at different strain rates and elevated temperatures, the pressure-volume-temperature (PVT) test, the deflection measurement and warpage simulation are conducted for the polypropylene based thermal plasticolefin(TPO). The PVT curves indicate that the coefficient of thermal expansion varies nonlinearly in the transition zone. The stress-strain curves show that the material has no obvious yielding. The Young′s modulus increases with the increasing of strain rate. The slope of the stress-strain curves in the unloading path is different from the initial Young′s modulus and dependent on the loaded strain limit, and it decreases when the loaded strain limit increases. The Chaboche viscoelastic constitutive relationship is adopt and modified to describe the mechanical behavior of TPO composite. The user subroutine UEXPAN and UMAT are developed to calculate the thermal and mechanical strain respectively. The warpage of injection molded part with complex geometry is simulated and compared with the measured result. The predicted distribution of deflection exhibits a good agreement with the measured one. The area, in which the excessive shrinkage happens, can also be predicted in the simulation.