Provided is a method for producing a gas oil composition which contains a decomposed gas oil base having poor oxidation stability, but rarely produces sludge or deposits and has high oxidation stability. The method is a method for producing a gas oil composition having an induction period of 60 minutes or longer, a sulfur content of 10 ppm by mass or less and a cetane value of 45 or more, which is characterized by comprising blending 0.5-15 vol% of a decomposed/reformed base having such properties that the total aromatic component content is 80-100 vol%, the bicyclic aromatic component content is 40-95 vol%, the 10 vol% distillation temperature is 160-250 C and the 90 vol% distillation temperature is 260-330 DEG C with 10-70 vol% of a decomposed gas oil base.