PURPOSE: To provide a process for preparing a recarburizer coke having low S content and low N content without deactivating a hydrogenation catalyst by subjecting a decant oil contg. considerable amts. of S and N to a plurality of specified steps.

CONSTITUTION: This process for preparing a recarburizer coke comprises the steps of: subjecting a decant oil 2 contg. considerable amts. of S and N to vacuum distillation to concentrate S and N to obtain a vacuum distilled gas oil fraction 6 having a predetermined b.p. and a residual oil 7 having a predetermined b.p.; exposing the gas oil 6 to severe hydrogenation conditions 10 to obtain a product 16 having lowered S and N contents; fractionating the product 16 in a first fractionating column 18 to produce a hydrocarbon fraction 22, a thermal tar fraction 32 and the like; mixing the thermal tar 32 with a hydrocarbon steam 46 from a coke drum 38 and then fractionating the mixture in a second fractionating column 48 to produce a coker gas oil fraction 58 and a thermal tar fraction 56; and subjecting the thermal tar 56 to delayed coking to produce a coke product 44.