Background: Morus nigra Linn is not only treated as health food but also medicine in Chinese history.Objective: Here, we have extracted and separated the heteroglycan to monosaccharides of the dry fruits. Method: After heteroglycan being hydrolysised, then were we derivatived the monosaccharides with 1- phenyl-3-methyl-5-pyrazolone (PMP), and then subsequently HPCE and HPLC were used to separate. HPCE, which held an uncoated capillary (d=75µ m) and detected by PDA at 245 nm with borate buffer, the voltage was set at 15 kV and capillary temperature was 25°. There is Yilite column (Hypersil BDS C18 5µ m, 4.6mm× 250mm) with HPLC and detected by UV at 245 nm and capillary temperature 25°.The High Performance capillary electrophoresis method and High Performance Liquid Chromatography method were compared on monosaccharide composition and quantitative determination of polysaccharide from the black mulberry. Results: Through several indicators including standard curve, precision, reproducibility, stability and recovery rate, the result of the two methods is basically consistent while they have complementary advantages. Conclusion: Both methods are suitable for the determination of the black mulberry polysaccharide, but each has its own merits.