Wedescribe a single-shot off-axis digital holographic microscopy based on a Michelson interferometric scheme for measuring temperature distribution of a microheater. The temperature variation of the micro heater substrate can result in the refractive index change. Therefore, the temperature can be obtained by detecting of reconstructing object phase image, which is dependent of the temperature distribution in real time. The experimental results demonstrate the feasibility and effectiveness of the off axis digital holography in various surface temperature distribution measurement applications.