In this paper, the effects of stress on the adhesive behavior of photoresist are described. The sources of internal stress of photoresist could be the shrinkage of photoresist during curing process and the shrinkage difference between the photoresist and the substrate. Due to high exothermicity of resin curing process, the temperature of photoresist is not uniform, which causes shrinkage difference in photoresist. Further more, when the substrate cools down, the difference of thermal expansion coefficients between the substrate and the photoresist would cause more stress. A digital phase-shifting interferometer is used to measure the curvature of substrate and then Stoney´s Formula is adopted to calculate stress. Then, a 2-D model is used to simulate temperature distribution, photoresist deformation and stress. Our results show that there is huge stress at the interface between photoresist and substrate and the stress can be reduced by anneal.