Abstract: The plastic finite elements method were used to analysis the themal stress of austenitic/feritic dissimilar metal joints. The effect of the groove angle, expanSion conefficient and the martensite layer in the fuSion zone on the themal stress were analysised. The results shown that the better thermal stress distribution comes from the joint with 60 degree groove angle. The thermal stress distribution in the martesite layer was mainly compressive stress and low tensile stress, the maximum tensile stress was occurred th the weld metal.