PURPOSE: To provide a catalyst having high decomposition activity at low temp. and with a long life in hydrogenolyzing hydrocarbons, particularly heavy oil.

CONSTITUTION: Zinc-introduced crystalline aluminosilicate is produced by making crystalline aluminosilicate obtained by dealkalization treatment of Y type zeolite come into contact with a solution which includes zinc and can elute aluminum in the zeolite skeleton. Hydrocarbons are hydrogenolyzed by using catalysts containing the zinc-introduced crystalline aluminosilicate, such as a catalyst where the zinc-introduced crystalline aluminosilicate as a carrier is impregnated with compounds of group VI and/or group VIII metals in the periodic table. Compared with the conventional hydrogenation catalysts, catalysts containing other metals, or catalysts containing aluminosilicate where only zinc oxide is deposited or zinc is introduced by ion exchange, the catalyst prepared by this method has higher hydrogenolysis activity and longer life.