Abstract: Based on large quantities of analytical data, the author studied the characteristics of the distribution of fatty acids, naphthenic acid and phenol in formation water and non-formation water of various strata and various are in northern Songliao Basin, and probed into the relationship between the contents of "fingerprint indicator" compounds and the accumulation of oil. Formation water can be closely related to hydrocarbon generation, migration and preservation.Organic acids are the conversion products of org-ganic matter to hydrocarbons, naphthenic acids, fatty acids were formed in source rocks and dissolved in pore water.Hence, the contents of fatty acids, naphthenic acids and phenol in oilfield water and subsurface water adjacent to oilfields increase towards oil bearing boundary, main source beds and reservoirs on the basis of regional geological survey. Oil and gas accumulation can be predicted by the change in contents of organic acids and phenol. Through practice it is proved that they are good indicators for hydrocarbon exploration and are of great importance in hydrogeochemistry in searching for oil and gas.