Abstract: The microstructure and mechanical properties of a new corrosion-resistant alloy C-22HS with high strength under standard heat treatment condition were studied by means of thermodynamic calculations, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and mechanical properties testing. The results indicate that C-22HS alloy under standard heat treatment condition is composed of equiaxed grains with different sizes. Major precipitations in C-22HS alloy are granular (Mo, Cr)₆C and dispersed distributing strengthening phase Ni₂(Mo, Cr). It is shown that C-22HS alloy under standard heat treatment condition possesses not only a higher strength but also a better plasticity and impact toughness. Its yield strength is much higher than that of C-22 alloy at room temperature or high temperature.