Considering the practical applications on superjunction (SJ) structure MOSFET under different temperature, a MATLAB based temperature dependent optimization approach for specific-on resistance (R on,sp ) under breakdown voltage (BV) of 900 V is proposed in this paper. Based on the constraints of two-dimensional (2-D) electric field distribution and impact ionization integral, the temperature dependent models of carrier mobility, impact ionization rate, intrinsic carrier concentration, and impurity incomplete ionization are adapted. MEDICI simulation is used for verification of the results, manifesting good agreement between theoretical calculations and simulation results at low aspect ratios (AR). Application instructions are provided based on our optimization in this paper, providing compromised design choices which satisfy BV and R on,sp under different temperatures.