Based on the fact that morphine has a significant inhibitory effect on Ag(Ⅲ) complex-luminol chemiluminescence system in alkaline solution and the effect is proportional to the concentration of morphine，a novel method was established for the determination of morphine by capillary electrophoresis coupled with indirect chemiluminescence detection.Under the optimized conditions,there was a linear range of 2.0-30.0 mg/L for morphine with a correlation coefficient(r) of 0.999 8 and the detection limit of 0.75 mg/L.The RSD(n=7) was 2.0%for morphine in a concentration of 20 mg/L.Combined with solid phase extraction,the method was successfully applied in the detection of morphine in urine and blood samples with the average recoveries of 109.0%and 101.3%,respectively.With the advantages of high-resolution,sensitivity and low-cost,the method could be used for the determination of morphine in urine and blood samples.