The effect of hydrogen on the irradiation behaviour of oboe dispersion Strengthened（ODS） ferritc steel has been studied by means of inn implantation at room temperature and in-situ observation with a low-voltage electron microscope.The microstructure of ODS ferritic steel before and ther hydrogen-ion implantation is not changed st room temperature

but changed obviously as the temperature robes tO 550℃

with the occurrence of precipitstion of chromium carbide.