The invention is martensitic stain less steel with high yield ratio and high ductility, the character is that it contains: C is not more than 0.06%, Cr 11-16.5%, Ni 3.50-6.0%, Mn is not more than 2%, Mo 0.5-2%, Si is less than 1%, the residue are Fe and a little impurity. The impurity includes Al, [O], [N], [H], S, P, the content of then are Al <0.15%, [O]<0.01%, [N]<0.03%, [H] is not more than 0.0005%, S is not more than 0.020%, P is not more than 0.025%. The invention can enhances the synthesis performance index (high density, high rigidity, high ductility and yield ratio, excellent welding processing property, and fatigue preventing property under water) greatly, it can ensure that the stress of large wheel is smaller than 1/3 of material yield ratio, the stress of large welding wheel is smaller than 1/2 of material yield density. It maintains the higher etching preventing property and sand grinding resisting property.