Abstract: To explore the chemical constituents of Diaphragma juglandis Fructus.,the compounds were separated and purified by repeated column chromatography on macroporous resin(MCI),reversed phase C₁₈,alkaline silica gel and preparative HPLC five methods of chromatography,^and^their chemical structures were identified by spectroscopic data including electrospray ionization mass spectrometry(ESI-MS)and nuclear magnetic resonance(NMR). The results showed that nine compounds were isolated from Diaphragma juglandis Fructus and they were 2-ethoxyjuglone(1),juglanin A(2),isosclerone(3),4-megastigmen-3,9-dione(4),3'-O-(E-4-coumaroyl)-quinic acid(5),dihydrophaseic acid(6),5'-O-(E-4-coumaroyl)-quinic acid(7),vanillic acid-4-O-β-D-glucopyranoside(8)and litchiol A(9). Compounds 4,5,7,8 and 9 were found in Juglans regia L. genus for the first time. The chemical composition of Diaphragma juglandis Fructus had been explored,which would lay the foundation for exploring its pharmacological activity,and be beneficial to the development and utilization.