Abstract: In this paper, the cracks in weld metal of product SAW butt joint of 14MnNbq steel were investigated with optical metallographic examination, SEM and micro-EMPA. The comparative evaluation of hot crack susceptibility for 14MnNbq and 16Mnq steels was conducted using varestrain test. The causes of hot crack formation and the affective factors were analyzed, and the measures to prevent weld metal of SAW welded joint of 14MnNbq from hot crack were proposed.