In this research, TP304 was treated by shot blasting under the pressure of 0.65MPa. The stainless steel shots used in the shot blasting experiment were in different sizes, separately with diameter 0.6mm and 1.2mm. To investigate the effect of shot blasting on the oxidation resistance behavior, steam oxidation experiments have been conducted to both original and shot blasting treating TP304s in 650°C and 25MPa. Then oxidation kinetics curve of each sample was measured by discontinuous weight method, morphology of oxide film was observed through SEM(scanning electron microscope), the component of the oxidation was measured by XRD(X-ray Diffraction), and the variation of Cr content in the oxide film was analyzed by EDS(energy-dispersive X-ray spectroscopy). According to the results, Oxidation kinetics curve in high temperature and pressure, expressed in original and shot blasting treating TP304s, both follow the principle of quasi-parabola and shot blasting can largely enhance TP304’s steam oxidation resistance in high temperature and pressure.