PURPOSE: To produce carburizing steel excellent in cold workability and fatigue resistance by heating steel having a specified compsn. in which Mo, Nb, Ti, Zr or the like are added and the carbon equivalent is regulated to a specified temp., subjecting it to hot rolling and thereafter executing specified cooling.

CONSTITUTION: Steel having a compsn. contg., by weight, 0.10 to 0.30 C, 0.05 to 0.15% Si, 0.3 to 1.0% Mn, ≤0.025% P, ≤0.025% S, 0.5 to 1.2% Cr, 0.20 to 0.50% Mo, 0.02 to 0.06% Al and 0.008 to 0.015% N and contg. one ore more kinds among 0.02 to 0.1% Nb, 0.02 to 0.2% Ti and 0.02 to 0.3% Zr, and the balance Fe with inevitable impurities and in which the carbon equivalent Crq=C +1.47Si+0.05MN+0.09Cr+0.61Mo+0.82Nb is regulated to ≤0.80% is heated to 800 to 950°C and is subjected to hot rolling. After that, this is hot rolled sheet is cooled at ≤30°C/sec cooling rate. In this way, the carburizing steel excellent in cold workability and fatigue resistance and free from the coasrsening of austenite crystal grains caused by high temp. carburizing treatment can be obtd.