Abstract: We used high performance liquid chromatography to determine malachite green (MG) in aquatic products, and optimized the factorsaffecting the recovery, such as extraction method, KBH4 amount, evaporation temperature, selection of solid phase extraction column and mobile phase, etc.. The sample was extracted by homogenate and ultrasonic instrument, reduced with 6% of KBH4, vacuum-evaporated at 40 ℃, purified with PRS solid phase, and determined by the mobile phase of 75% acetonitrile with 25% ammonium. Thus, weobtain an accurate method which has simple pretreatment but high recovery.