PURPOSE: To produce a high strength and high toughness UOE steel pipe excellent in SR characteristics by subjecting a base material having a specified compsn. to submerged arc welding to obtain a weld metal having a specified compsn. and thereafter executing specified stress relief annealing.

CONSTITUTION: A base material contg., by weight, 0.02 to 0.10% C, ≤0.50% Si, ≤2.00% Mn, ≤0.020% P, ≤0.0020% S, ≤0.045% Nb, ≤0.08% V, ≤0.05% Ti, ≤0.0010% B, ≤0.50% Mo, ≤0.0050% N, ≤0.0030% O and Fe is subjected to submerged arc welding of one pass on the inside and outside faces with an Mo-Ti-B welding wire. Thus, a weld metal having a compsn. constituted of 0.01 to 0.06% C, ≤0.6% Si, ≤1.60% Mn, ≤0.02% P, S and Nb, ≤0.1% V, ≤0.02% Al, ≤1.5% Ni, ≤0.05% Ti, ≤0.0030% B, ≤0.5% Mo, ≤0.10% N, 0.015 to 0.050% O and Fe and in which Pcm in formula I is regulated to 0.13 to 0.18 and α in formula II is regulated to ≤1 is obtd. The UOE steel pipe obtd. by the same is subjected to stress relief annealing of heating the same at 580 to 750°C for ≥10min and thereafter executing cooling at ≤1°C/sec cooling rate.