A rapid and economic ultra performance liquid chromatography-tandem mass spectrometry method is developed and validated for the determination of melamine in milk and milk products.The method includes a simple acetonitrile-water extraction,and ultrasound treatment and dichloromethane liquid-liquid extraction to remove protein and fat.The purified extract is further diluted before injection on ACQUITY UPLC BEH HILIC.A positive ion electrospray ionization(ESI+) and multiple reaction monitoring mode(MRM) are then applied.The samples are quantified by external standard method.A total analysis was done within 1.2 min with a good linear relationship(r>0.9991).The limit of detection and the limit of quantification were 0.005 and0.017 mg/kg,respectively.The spiked recoveries are within 91.3%~97.1% at the spiked levels of 10~400 μg/L for melamine with relative standard deviation(RSD) below 9.03%.This method is rapid,economic,accurate and sensitive,suitable for screening and detection melamine in milk and milk products.