Cyclic plastic deformation behaviour of 316L steel with an average grain size ∼ 30 μm was investigated at high temperature (873K) under completely reversed straining at ±0.5% strain amplitude with a constant total strain rate of 3 × 10−3S−1. Maximum true tensile stress initially increased due to cyclic hardening until 100 cycles, then stress saturation occurred and finally failed at 1250 cycles. Deformation microstructure varied significantly with imposed fatigue cycles. Occurrence of planar glide and isolated dislocation walls were observed in the initial hardening stage, while dislocation walls accompanied by connected equiaxed dislocation cells were predominant in the saturation stage. The deformation microstructure at failure stage mainly composed of elongated dislocation cells and diffusive dislocation walls. Dislocation densities estimated by X-ray diffraction were ∼ 1013m-2.