Abstract: Zr-Mo micro-alloyed 310S stainless steel was prepared and treated by solution at different temperatures (1 050-1 150 ℃), and by solution at 1 150 ℃+stabilization at different temperatures (950-1 050 ℃). The microstructure and corrosion resistance of the test steel treated with different heat treatment were studied. The results show that the microstructure of the tested steel after solution was uniform austenite equiaxed grains, and there were a large number of annealing twins in the grains; strip-shaped or clumpy (Zr, Mo) C phase and massive Zr(C,N) phase precipitated from the grain boundaries or grains. The microstructure of the tested steel after solution treatment at 1 150 ℃ and stabilization treatment at different temperatures was similar to that after solution treatment, but the number of precipitated phases increased; a large number of hammer-like M₂₃ C₆ phase precipitated from the grain boundaries after stabilization treatment at 950 ℃. Stabilization treatment at 950-1 050 ℃ had little effect on the uniform corrosion resistance of tested steel. With the increase of stabilization temperature, the inter-granular corrosion sensitivity of the tested steel decreased, and inter-granular corrosion resistance was improved.