Eel (Anguilla bicolor) is a fish that has high enough nutrients such as fatty acids, vitamins and minerals. This study aims to determine the composition and fatty acid levels of eel (Anguilla bicolor) in the elver and silver eel phases from the Palu River and Lake Poso. The research sampling technique using purposive sampling method based on type, weight, size and place of collection and samples were analyzed using the Gas Chromatography tool to transform extracts the fat into fatty acid methyl esters. The results of the analysis of fatty acid types of eel fish (Anguilla bicolor) in elver eel phase from Palu river and Lake Poso were respectively, saturated fatty acids 6.085g/100g and 5.543g/100g, monounsaturated fatty acids 5, 157g/100g and 7, 817g/100g, polyunsaturated fatty acids 1, 265g/100g and 1, 950g/100g. Whereas in the silver eel phase respectively, saturated fatty acids 3, 829 g/100g and 4, 177g/100g, monounsaturated fatty acids 2, 035g/100g and 2, 859g/100g, polyunsaturated fatty acids 3, 370 g/100g and 0, 524g/100g. The results showed that the fatty acid levels of the eels fish in the elver and silver eel phases from Palu River and Lake Poso in the elver eel phase were significantly different, namely myristic acid, miristoleic acid, pentadecanoic acid, heptadecanoic acid, linoleic acid and linolenic acid, for. While the silver eel phase the sample taken from Palu River and Poso Lake were significantly different, namely, lauric acid, stearic acid, oleic acid and myristic acid.