To investigate the reasons why the cross section of colored mistletoe herb can be green.Methods:The green components were extracted by solvent, and the property of the components were determined by ultraviolet light, fluorescent light-visible lights wavelength scanning and thin layer chromatography, and the content of active components was determined by HPLC.Results:The 95% ethanol extract of green colored mistletoe herb pieces contained the green components. The ethanol extract had red fluorescence under 365 nm UV light and the wavelength of the maximum absorption peak was 665 nm. The Rf value and color of spot on extract correspond with chlorophyll. The syringin in the green decoction pieces of colored mistletoe herb reached Chinese Pharmacopoeia standards.Conclusion:The green color in the cross-section of colored mistletoe herb was caused by chlorophyll, and there was no declination of syringin. There should be more studies on the reasons why the chlorophyll was saved so well with the special green color. Whether the related description on Chinas pharmacopoeia should be revised should be further discussed.