Unclamped inductive switching test is crucial to evaluate the thermal reliability and stability of power device in avalanche mode. In this study, unclamped inductive switching capability of 1200V SiC-MOSFETs has been studied in the condition of 400V DC bus and 1mH inductance. Two simple methods include fixed peak current and alterable peak current are used to explore the maximum junction temperature during avalanche mode in different ambient temperature range from 300K to 450K. The fit curves of experimental results indicate that SiC-MOSFETs can endure almost three times higher lattice temperature compared with silicon power device, which shows the best candidate ability to the power switching application.