The effects of hold time in tensile strain on the behavior of high temperature low cycle fatigue in AISI 304L stainless steel at 865K were investigated in Ar atmosphere under the axial strain control at a strain rate of $4×10^{-3}/s$. Under triangular continuous cycling, fracture was occurred by the transgranular propagation of fatigue crack initiated at the specimen surface. In the fatigue test with 30 min. hold time at the peak tensile strain, the fatigue crack is observed to be propagated by transgranular mode only and no grain boundary creep cavities are observed. But when the critical fatigue life under hold time is compared with that of continuous test, it is significantly decreased with decreasing plastic strain amplitude. From the experimental results, decrease in the fatigue life with tensile hold time compared to continuous cycling could be explained as follows; reduction of the number of cycles to the crack initiation is considered to the easier formation of the persistent slip band during tensile hold time. And decrease in the number of cycles to the crack propagation is considered the increased crack growth rate caused by increase of the crack tip opening displacement under tensile hold time.
