Abstract:Objevtive: To determine the contents of morusin in Sangbaipi (Cortex Mori) of different commercial grades and species and obtained from different regions. Method: Contents of morusin were determined by HPLC on an Alltima C18 column (4.6 mm×250 mm, 5 μm) with acetonitrile-water (58∶42) as mobile phase. UV detection was conducted at 270 nm. Result: The amounts of morusin were found to vary among samples of Cortex Mori bearing a yellow-brown outer layer and those without the yellow-brown cork layer. The morusin contents were also related to the thickness of Cortex Mori. Conclusion: The method was simple, reproducible and reliable. It can be applied to the quality assessment of Cortex Mori.