Abstract: Based on the analysis on the possible structures of welding joints connecting dissimilar steels SA213TP304H and 12Cr1MoV with reference to the Schaeffler's diagram, a rational welding procedure is worked out.The welding of SA213TP304H steel and 12Cr1MoV steel joints in the boiler of Shaoguan Power Plant is carried out according to the procedure. The 140 dissimilar steel tube welds prove to be intact in the operation of one and half a year without bursting as their predecessor.