Abstract: Physic-chemical indicators of swill oil and other qualified edible oils were compared.As shown by the analysis on physical and chemical indicators,the moisture content in the swill oil was 35 times as high as that in the Jinhao tea-seed oil;the peroxide value of the swill oil was 5.5 times as high as that in the Jinhao tea-seed oil;and acid value of the swill oil was 25.2 times as high as that in the Jinhao tea-seed oil.And the colors and relative density of the swill oil were better than that of the edible oils.The iodine value of the swill oil was lower than that of other edible oils.After being frozen,the swill oil had precipitates and cloudy grease.The electrical conductivity of the swill oil was higher than that of the edible oils.Thus,determination of electrical conductivity can be used to distinguish swill oil from edible oils.