To analyze the principle of profile formation for grating masks and the evolution of photoresist response curves, a simulation model of profile formation for grating masks in development was established. Based on the difference of photoresist dissolution rate in the different regions, the complete photoresist curve was divided into three sections, the effect of each section in the profile formation of grating masks was analyzed, then the simulation surface-relief profile model was presented. The experimental results indicate that the groove profile inclines to be rectangular or trapezoidal when the nonlinearity of photoresist response curve is remarkable, and the groove depth is mainly decided by the initial photeresist thickness. The groove profile is sinusoidal when the linearity response is strong, and the groove depth is also always decreased under this condition. The experiment shows that the proposed model can predict the profile evolution for the different photoresist curves and it provides a directive theory for fabricating the various profile masks during development according to the different photoresist response curves.