Abstract: Grafted clonal plants of three Triadica sebifera cultivars ‘Pu Hongjiu’ ‘Pu Dazi’ and ‘Hui Huang’ were served as experimental materials, measuring and analyzing the chromaticity values, pigment content and soluble sugar content of leaves at different stages to explore color change pattern of the autumn leaves and physiological regulation mechanism of different colors of T. sebifera cultivars. The results showed that （1） the L* values (Lightness) of ‘Pu Hongjiu’ and ‘Pu Dazi’ leaves increased first and then decreased, the a*（Red-Green Hue）and b*(Yellow-Blue Hue) values of which presented an increasing trend with the lapse of time. The chromatic value of the cultivar ‘Hui Huang’ showed an increasing trend, the L* and b* values are generally higher than those of ‘Pu Hongjiu’and ‘Pu Dazi’. （2） During the process of leaf color change, the chlorophyll and carotenoid content of the leaves of three cultivars showed a decreasing trend, while the anthocyanin and soluble sugar content showed an increasing trend with significant changes observed in S6 (November 4th) (P<0.05). （3） The ratio of chlorophyll to carotenoid content showed a decreasing trend, while the ratio of anthocyanin to chlorophyll content and anthocyanin to carotenoid content showed an increasing trend. （4） The results of correlation analysis revealed that there was a significantly negative correlation between the chromaticity value and chlorophyll content, which had significantly positive correlation with anthocyanin and soluble sugar contents （P<0.05）. The results above demonstrated that the color change of T. sebifera leaves in autumn are related to pigment content and the ratio between pigments. T. sebifera leaves appear red （85.87, 128.91） or purple （49.33, 60.09） when the ratios of anthocyanins to chlorophyll and anthocyanins to carotenoids are high, leaves turn yellow (12.34, 14.17) when the ratios are low. The research outcome can provide reference for the rational utilization of T. sebifera cultivars resource.