In order to explore the excellent germplasm resources of Cucurbita pepo L. and improve the selection efficiency of elated to emerald (vivid) green appearance quality, this study conducted a classification of different skin color of tender fruit used a color difference instrument on 54 self bred lines of zucchini created by our unit, and based on seven representative materials ( including four key ),the correlation between chlorophyll synthesis metabolism and its skin color formation in the skin of tender fruit was analyzed .The results showed that chlorophyll was the main pigment that determined the skin color of tender fruit of partial white, light green, emerald (vivid) green, and deep colors (green and dark green). Among them, the content of chlorophyll a accounted for 49.20% to 60.58% of the total content. The content of chlorophyll a was the main reason for determining the deep and light skin color. The emerald (vivid) green skin with the most vibrant and greenish color had significantly higher chromaticity value (C) than other skin color, while chlorophyll a/b and the red green value (a*) were significantly higher and lower respectively than partial white, light green, and dark green. The chlorophyll of synthesis of skin of tender fruit in dark green, emerald (vivid) green, and partial white was hindered by two points: PBG→Urogen III, and Coprogen III→Proto-IX. However, the latter transition stage was the main reason in the chlorophyll synthesis blocked, and sudden decrease of chlorophyll content of partial white and emerald (vivid) green. There was a significant correlation between chlorophyll synthesis weaken and chlase in chlorophyll metabolism enzyme activity enhance degradation, superoxide dismutase (SOD) and catalase (CAT) activities weaken, those also the reason of partial white skin color. SOD and CAT activities in antioxidant enzymes were significantly correlated with the chlorophyll content of the skin of tender fruit, thereby delaying the rate of chlorophyll reduction in emerald (vivid) green and dark green. The results of this study provide theoretical basis and technical support for in-depth analysis of different skin color of tender fruit especially the color formation mechanism of emerald (vivid) green, and for the exploration and utilization of relevant excellent and specific resource materials.