Aim: To study the chemical constituents of the roots and stems of Zanthoxylum nitidum (Roxb.) DC.. Methods: Silica gel and Sephadex LH-20 column chromatography were used to isolate and purify the constituents. Various spectroscopic analyses were involved to elucidate the structures. Results: Two benzo[c]-phenanthridine alkaloids, named 8-(2'-cyclohexanone)-7, 8-dihydrochelerythrine (1) along with a known compound 8-(1'-hydroxyethyl)-7, 8-dihydrochelerythrine (2) were isolated from this plant. Conclusion: Compound 1 is a new compound. © 2009 China Pharmaceutical University.