Abstract: In this paper,the angle restraint method is applied to improve the welding HAZ toughness in 15MnMoVNREs steel.It is found that the Charpy-V impact energy readings of the restrained condition are increased over 20% compared to those of non-restrained condition from lower temperature to room temperature.This is due to the fact that the restraint gives rise to the increase of Bs temperature,and so the change in morphology and microstructure of the M-A constituents in welding HAZ.