Abstract: A method for manufacturing an ultra-high-strength cold-rolled steel sheet having desirable delayed fracture resistance, which comprises: preparing a material consisting essentially of 0.1 to 0.25 wt. % carbon, up to 1 wt. % silicon, 1 to 2.5 wt. % manganese, up to 0.020 wt. % phosphorus, up to 0.005 wt. % sulfur, 0.01 to 0.05 wt. % soluble aluminum, 0.0010 to 0.0050 wt. % nitrogen, optionally at least one of Nb, Ti or V, optionally at least one of Cu, Ni, B, Cr or Mo, the balance being iron and incidental impurities; subjecting the material to a hot rolling, a pickling and a cold rolling to prepare a cold-rolled steel sheet; and subjecting the cold-rolled steel sheet to a continuous heat treatment which comprises: subjecting the cold-rolled steel sheet to a soaking treatment at a temperature of Ac.sub.3 to 900.degree. C. for 30 seconds to 15 minutes, quenching the cold-rolled steel sheet at a quenching rate of at least 400.degree. C./second from a temperature of at least a lower limit temperature (T.sub.