Abstract: Described in the article are the common defects of the SAWL pipe weld joint,including undercut,weld porosity,lack of fusion in weld,lack of penetration,overlap,burn through and weld flaw,etc. The causes for such defects are investigated,and accordingly,actions for quality control to be taken before and during the welding operation are put forwarded. Based on the analysis,it is concluded that the above mentioned defects could be prevented,and the welding quality improved,providing that proper welding material is selected,the welding bevel surface and the welding wire are completely cleared of any dirt,and the bevel geometric dimensions are properly controlled.