Abstract: A simple, sensitive and accurate method for the separation and determination of the lignans: podophylltoxone (Ⅰ), isopicropodophyllone (Ⅱ), picropodophyllone (Ⅲ), dehydropodo-phyUotoxin (Ⅳ), picropodophyllin (Ⅴ), podophyllotoxin (Ⅵ), 4′-demethylpodophyllotoxin (Ⅶ)and diphyllin (Ⅷ) is described. The sample solution was applied at a point 1 cm from the bottom edge of the HPTLC silica gelplate (10 cm × 10 cm), dichloromethane--diethyl ether (4:1) was used as the developing solvent.The plate was saturated for 30 min and then developed twice for 9. 5 cm using ascending technique. The plate was sprayed with 2. 5% ammonium ceric sniphate--20% nitric acid and toasted for 15 minat 120°C, then fumigated with ammonia solution for 20 min at room temperature to intensify thecolor. The spots were scanned with a Shimadzu CS-930 TLC scanner. The contents of eight lignans in Diphylleia sinensis was calculated by comparison with standards spotted on the same plate. The standard curves were linear in the ren of 0. 48～2. 52 μg for the eight lignans. The method has been applied to the analysis of various samples and can be used for the quality control ofsinensis, podophyllum and dysosma preparations used in clinic.