Abstract: Accelerated corrosion tests for Q235 steel plates were carried out in situations of acid spray in natural atmosphere, constant temperature and humidity, neutral salt spray in box and neutral salt spray in natural atmosphere. Then the effects of corrosion on the mechanical behaviors of corroded steel plates were studied by tensile testing. The results indicate that the tensile strength and yield strength of steel plates were not affected after corrosion when the corrosion ratio was no more then 4%, and obeyed a linear degradation trend with the increase of corrosion ratio when corrosion ratio was more then 4%; the break elongation also degraded with the increase of corrosion ratio. But the effect of corrosion on elasticity modulus of corroded steel plates needs further study.