Abstract: Duplex stainless steel UNS31803 was welded by shielded metal arc welding (SMAW). Microstructure and properties of the welded joint for UNS31803 duplex stainless steel by SMAW were analyzed by means of metallographic examination, mechanical property test, hardness test and corrosion resistance test. The results show that the microstructure of the weld seam were ferrite+austenite, and without σ phase precipitation when proper welding parameters were adopted. The welded joint had excellent mechanical properties, and the ferrite content of the weld seam and the heat affected zone was within the reasonable range of 35%-65% (volume fraction). In 6% (mass fraction) FeCl₃ solution at 22℃, the different regions of the welded joint had good corrosion resistance.