A simple, rapid, and sensitive HPLC-UV method was developed for qualitative and quantitative analysis of 12 coumarin compounds (skimin, scopolin, scopoletin, umbelliferone, 6,7-dimethoxycoumarin, coumarin, psoralen, xanthotoxin, 5,7-dimethoxycoumarin, pimpinellin, imperatorin, and osthole) in bamboo leaves. The samples were extracted with ethanol-water (70 + 30, v/v) by ultrasonication and purified by Florisil SPE. The method was validated for linearity, LOD, LOQ, accuracy, precision, and recovery. The standard curves in the corresponding ranges had good linearity. LOD was at the range of 0.19 to 0.85 mglkg and LOQ 0.64 to 2.82 mg/kg. The values of RSD for accuracy and intraday and interday precision were less than 3%, except for 6,7-dimethoxycoumarin. Recoveries from spiked samples at 30, 20, and 10 mg/kg in Dendrocalamus giganteus Munro were higher than 70%, except for scopoletin, 6,7-dimethoxycoumarin, and coumarin. The method was validated using field-collected samples taken from Beijing and Changning Counties, SiChuan, China. Six coumarins, namely, skimin, scopolin, scopoletin, umbelliferone, coumarin, and pimpinellin, were found in the extracts of 11 species of bamboo leaves. The concentrations of total coumarins were in the range of 8.67 to 99.2 mg/kg. The maximum concentration of total coumarins was found in Bambusa pervariabilis, and the minimum was in