Abstract: OBJECTIVE To isolate and identify the chemical constituents of twigs and leaves of Caesalpinia sinensis. METHODS Compounds were purified and separated through silica gel and Sephadex LH-20 gel column chromatography, and other modern chromatographic techniques. Their structures were identified on the basis of NMR spectral analysis and comparing with the data in the literatures. RESULTS Twelve compounds were obtained and identified from twigs and leaves of Caesalpinia sinensis, they were caesaloside A(1), 2β-thoxyclovane-9α-ol(2), 2β-methoxyclovan-9α-ol(3), 8(17),13-ent-labdadien-15→16-lactone-19-oic acid(4), erythrodiol(5), 5,7,3',4'-trahydroxy-3-methoxyflavone(6), quercetin(7), apigenin(8), luteolin(9), ethyl-3,5-dihydroxy-4-methoxybenzoate(10), ethyl gallate(11) and gallic acid(12), respectively. CONCLUSION Compounds 1 and 2 are new compounds, and the other 10 compounds were isolated from this plant and reported for the first time.