Abstract: 【Objective】In this study, the leaf color variation pattern of the open pollination progenies of the ornamental crabapple was studied to provide reference for half-siblings and breeding cultivars of ornamental crabapples. 【Method】Three green leaf ornamental crabapple cultivars(‘Winter Gold', ‘Winter Red' and ‘Red Jewel')and the female parent of the open-pollinated half-sib progenies were used as materials. The Minolta colorimeter was used for measuring the leaf color parameters of 120 half-sib progenies, optimizing the dynamic change of leaf color. 【Results】① Based on the L^*, C^* and h^° color parameters of the upper leaf from May to August, the CIELCH color space dynamic distribution map was constructed. It was found that the leaf color parameter loci of ‘Winter Gold' half-sib progenies was the most dispersed as well as most abundant; bright green and red leaves were not present in the female parent. ② Based on the leaf color parameters(L^*, C^* and h^°)of upper leaves in May, a leaf color clustering analysis was constructed. It was found that the half-sib progenies can be divided into two major color groups and five sub color groups at the Euclidean distance level of 19. The green group occupied the highest proportion(92.5%), which included the brown green sub group, dark green sub group, and bright green sub group. The red group included the purple and brown sub groups. ③ Based on the results of the cluster analysis and color parameters, the evaluation system for the green groups and red groups of the half-sib progenies, respectively, was constructed. Based on the high color brightness, high color chroma value, and high color stability, we found that ‘A03' and ‘A09' of ‘Winter Gold' half-sib progenies, ‘D21' of ‘Winter Red' half-sib progeny, and ‘C10', ‘C26' and ‘C29' of ‘Red Jewel' half-sib progenies were the pre-selection plants in green series. From the perspective of low hue angle and color continuity, we observed that the ‘A37' of ‘Winter Gold' half-sib progeny in the red groups had higher ornamental value of the pre-selection plants, compared with the other ornamental crabapple cultivars. 【Conclusion】Through open pollination, the genetic diversity of the half-sib progenies of ornamental crabapples has greatly increased, increasing the diversity of leaf color. The parameter color space has been used as the preferred evaluation method, which is more intuitive and visualized, and can be used as a practical method in the production of ornamental crabapples and breeding of new varieties.