Welding deformations of real structures are complicated and the accurate prediction of welding deformations has been a difficult problem. The equivalent load method is presented in this paper. The method uses the FE method combining the inherent strain theory and the experimental results for accurate and efficient analysis. A simplified elastic plastic analysis model, bar-spring model is used. It is showed that the highest temperature and the degree of restraint change the distributions of the inherent strains in the welded region. Applying the equivalent loads induced by the inherent strain on the structure, the final deformations are calculated by FE analysis. The results in this paper have been supported by the results of C.H.LEE and the experimental data.