According to the design theory of orthogonal experiment, the heating time, heating temperature, adding amounts of salt and monosodium glutamate were selected as the factors which affected oil quality to design the orthogonal experiment. The soybean oil was heated under different conditions with iron pan or non-stick pan. The acid values and carbonyl values of the heated oil were detected to analyze the effect of the factors on the oil quality. The results showed that heating time had the highest effects on the acid value and carbonyl value of oil, followed by heating temperature,and the amounts of salt and monosodium glutamate were the minimum influence factor to acid value and carbonyl value. The acid value and carbonyl value of oil heated in non-stick pan were higher than that in iron pan, which showed that the heating medium had influence on the quality of oil, and the oil quality changed less in the iron pan than that in non-stick pan.