Chemical characteristics of lipids extracted from Petambori fish and composition of that fish were analyzed by standard method. Various chemical properties e.g. saponification value, saponification equivalent value, acid value, percentage of free fatty, ester value, acid iodine value, peroxide value, ester value, thiocyanogen value, titre value, unsaponifiable matter, Henher value, Polenske value, Reichert-Meissl value, cholesterol content etc. of the lipid sample were determined and compared with those of different standard oils. Palmitic acid, Stearic acid and Oleic acid were observed at fatty acid composition of the sample by Thin Layer Chromatography (TLC). Percentages of protein and mineral (N, P, K, Ca) in the liver lipid of Petambori fish were studied by modified kjeldahl method.