The present invention relates to a temper rolling oil which comprises:(A) a water-soluble cationic compound prepared by neutralizing a condensation product obtained by reacting the following compounds 1 to 3 with each other by heating:1. an aliphatic dicarboxylic acid,2. at least one amino compound represented by the following formulae (a) to (c): ##STR1## 3. a particular polyethyleneimine, with an oxoacid of phosphorus, (B) an aqueous rust preventive, and(C) water.The present invention is also concerned with a method of temper rolling which, comprises of conducting temper rolling at a reduction ranging from 0.5 to 30% using a dilute solution prepared by diluting a temper rolling oil of the kind as described above, so that the concentration of a water-soluble cation compound contained therein is 300 to 5,000 ppm.