Abstract: Five Malus spp.,including Malus ‘Radiant’,Malus halliana,Malus micromalus,Malus ‘Spring Sensation’,Malus hupehensis,were used as test materials.The petals at different blooming stages were collected, and the processes of flower color changing were observed.The contents and kinds of polyphenols in petals were detected through spectrophotometer and high performance liquid chromatography.The study objects are aimed at ascertaining the key substance influencing the flower color difference and fading of different Malus spp.,in order to provide reference for exploring the fading mechanism and breeding of flower color.The results showed that among five Malus spp.,the flower colors of Malus ‘Radiant’ were the reddest, correspondingly, brightness L^* values were the lowest and total anthocyanin contents were the highest.The flower colors of Malus hupehensis were nearly white during blooming process, correspondingly, L^* values were the highest and total anthocyanin contents were extremely low.Therefore, the difference of anthocyanin contents was the key reason for the difference of Malus spp.flower colors.The flower colors of Malus spp.faded significantly, and total phenol contents, total flavonoid contents, and total anthocyanin contents decreased evidently during blooming process.There were abundant anthocyanins, flavonols, flavanols, flavonones, phenolic acids, and dihydroflavonols detected in petals.The cyanindin-3-O-galactoside was the main anthocyanin in Malus spp.petals, and its contents were significantly decreased during blooming process, which was the main subtance for the flower fading.Also, the high levels of quercetin-3-O-glucuronide, hyperoside, chlorogenic acid, and phloridzin were detected in petals.It was speculated that these polyphenols could assist anthocyanin color.