Abstract: A heat conduction equation under high-cycle fatigue loadings was established using sheet assumption within thermodynamic framework. Dissipated energy per cycle, correlated with fatigue damage, could be deduced from temperature field data of specimen and real-time load signal. Then, taking 316L stainless steel for example, the dissipation energy per cycle variations were in-situ monitored during each high-cycle fatigue test under different stress levels. Dissipated energy versus fatigue lifetime curve shows the same pattern as the traditional stress versus fatigue lifetime curve. A new energy method was developed to predict high-cycle fatigue limit. The high-cycle fatigue limit determined by dissipated energy measurement was close to the experimental fatigue limit.