This survey was conducted to monitor the adulteration of sesame oil circulated in Gwangju, 2007. A total of 60 samples was tested by analysis of fatty acid composition. Of these samples, 22 were from large-scale manufacturer, 25 were from small-scale manufacturer and 13 from Bangagan. First of all, in goods manufactured by large-scale company, there are no sesame oils where linolenic acid (C18:3) exceed regulatory guidance (0.5%). 5 samples from small-scale manufacturer contained linolenic acid from 0.90% to 8.38%, which means that they have other cooking oil, such as corn oil, soybean oil and rape seed oil. Among Bangagan goods, only one sample have 1.20% of linolenic acid. On the other hand erucic acid (C22:1) was not detected in 60 samples at all, which means that they were not adulterated with rape seed oil. And among 6 samples of exceeding 0.5% of linolenic acid and 12 samples from Bangagan, 13 of them had benzo(a)pyrene from 0.2 μg/kg to 0.7 μg/kg and the other 5 samples did not.