A sensitive chemiluminescence(CL) method was developed for determining melamine in urine and plasma samples based on the fact that melamine can remarkably enhance the chemiluminescence of Luminol-K3 Fe(CN)6 system in alkaline medium.The determination conditions were optimized.Under optimum conditions,the chemiluminescence intensity had a good linear relationship with melamine in the range of 9.0 × 10 9 7.0 × 10 6 g/mL with a correlation coefficient of 0.9992.The detection limits (3σ) were 3.54 ng/mL for urine sample and 6.58 ng/mL for plasma sample.The average recoveries of melamine were 102.6％ for urine sample and 95.1％ for plasma sample.Melamine in samples was extracted with liquid-liquid extraction procedures and the assay results coincided very well with that determined with flow injection chemiluminescence method.The method provides a reproducible and stable approach for sensitive detection and quantification of melamine in urine and plasma samples.