Abstract:The differences of polysaccharide in different periods and different parts in the late blooming stage of Rehmannia glutionsa flower were compared.The high-performance liquid chromatography（HPLC）fingerprint of the pre-column derivatization of polysaccharides from Rehmannia glutionsa flower was established for the monosaccharide composition of polysaccharides.The research would be provided experimental basis for the further development of Rehmannia glutionsa flower.The content of polysaccharide was determined by phenolsulfuric acid colorimetry.The monosaccharide composition of polysaccharides in different parts of Rehmannia glutionsa flower in blooming stage and in different stages were analyzed by using 1-phenyl-3-methyl-5-pyrazolinone（PMP）derivatization after hydrochloric acid hydrolysis.The polysaccharide content in bud stage was 3.98%-4.93%.The polysaccharide content in blooming stage was 3.65%-3.78%.From bud stage to blooming stage，the content of polysaccharide increased first and then decreased.It reached the maximum at the later stage of flower bud.The average polysaccharide content was higher in bud stage than that in the blooming stage；The contents of polysaccharides in flower lobes，upper part of flower barrel and lower part of flower barrel were 3.84%，4.05% and 2.93%.And the average polysaccharide content of the upper part of flower barrel was the highest.10 common peaks were found and 4 peaks were identified in high-performance liquid chromatography（HPLC）fingerprint of precolumn derivatization，which were rhamnose，D-glucose，D-galactose and arabinose.The monosaccharides in the polysaccharides were similar，and the similarities of 9 samples were all above 0.95.As a non-medicinal part of Rehmannia glutionsa，the medicinal and edible value of its flower should be developed.