Abstract: Effects of stress level, loading velocity and loading process on room temperature creep properties of 1Cr18Ni9Ti steel tube and influences of room temperature creep and loading process on yield stress were studied by using microcomputer control electric tensile tester. The results show that room temperature creep strain of the steel tube increased with the increase of stress level and loading velocity. The loading process could decrease the secendary room temperature strain . The density of the fixed dislocation increased after different loading processes were carried on the steel tube, and the subsquent secondary tensile process could raise the yield strength of the steel tube.