The axial compression column curves were divided into 4according to residual stress distribution mode of different section shapes in current design code of steel structures（GB50017-2003）.It is shown that the influence of residual stress distribution on the load bearing capacity is very significant.The residual stress will redistribute due to the high temperature in fire.In order to obtain the load bearing capacity of steel members after exposure to fire

it is necessary to investigate the residual stress distribution in steel section after exposure to fire.The experimental study was carried out on residual stress of steel section made from Q235 and Q460steel before and after exposure to fire by employing sectioning method.The residual stress distribution mode was obtained and the comparison was made before and after exposure to fire.The study shows that the residual stress is reduced significantly by high temperature

but the distribution mode keeps same after exposure to fire.For hot-rolled Q235H-shaped section

the residual stress distribution mode is‘V’shaped in flange and is declining to‘U’for web

and for welded Q460 Hshaped section

the residual stress distribution mode is declining to‘W’shape in flange and is also declining to‘U’in web.