Abstract: The petroleum ether, n-hexane, ethanol, n-hexane + ethanol （3∶1, v/v） were used to extract oil from large yellow croaker, and the best extraction method was obtained through single factor experiment and response surface optimization method. The physical and chemical indexes of fish oil were detected, the gas chromatography-tandem mass spectrometry was used to analyze the fatty acid composition, tocopherol, sterol, and squalene of fish oil, and cell experiment was used to detect the absorption ability of the skin to large yellow fish oil. The results showed that for four different methods, the fish oil extracted from petroleum ether was slightly better than that of the other three methods. When the extraction temperature was 70 ℃, the extraction time was 121 min, and the organic solvent volume fraction was 40 mL, the maximum yield （35.18 ± 0.16） % of fish oil could be obtained. A total of 17 fatty acids, 4 types of tocopherol, sterols （cholesterol）, and a small amount of squalene were detected by gas chromatography-tandem mass spectrometry, of which the essential fatty acid-linoleic acid was （12.20 ± 0.04） %, and α-tocopherol reached 4.23 mg/100 g. The thermal denaturation temperature of fish oil was 121.60 ℃, which was non-toxic to the skin, and could promote the absorption capacity of the skin, enhance skin gloss,make the skin moist and delicate, and relieve the dry skin.

Key words: large yellow croaker, extraction rate, response surface methodology, peroxide value, tocopherol