PURPOSE: To provide a titled welding wire with which the specifications for the strength and toughness in a weld zone are stably obtd. by limiting the content of P and S and limiting the range and index value of C, Si, Mn, Cu, Ni, Cr, Mo and V.

CONSTITUTION: A wire for electroslag welding for an extra thick low alloy high tensile steel plate consists of 0.06W0.18wt% C, 0.05W0.45% Si, 0.60W1.80% Mn, 0.14W0.38% Cu, 0.10W0.50% Ni, 0.10W0.45% Cr, 0.10W0.60% Mo, 0.01W0.05% V, ≤0.020% P, ≤0.020% S, and the balance Fe and inevitable impurities. The condition 41C+5Si+8Mn+28Cu+5Ni+2Cr+7Mo+32V≥28 (element symbols are the weight % of respective components) is satisfied in said wire. The weld metal having stable toughness and tensile strength is obtd. in electroslag welding of the extra thick low alloy high tensile steel plate by the above-mentioned wire.