A method for determination of succinic acid, glutaric acid and adipic acid in a new compound liquid fertilizer by gas chromatography is described. The sample after dried at 80 degrees C was extracted by ethyl alcohol, and then esterified in the presence of BF3. The esterified derivatives were injected into a gas chromatograph with a 5% SE-30 packed column, programmed from 140 degrees C (held for 1 min) to 160 degrees C (held for 6 min) at a rate of 6 degrees C/min. Internal standard was diethyl malonate. Calibration curves of the three diethyl esters were linear in the ranges of 2.3-9.3 micrograms, 10.8-43.2 micrograms and 2.8-11.0 micrograms respectively.