Abstract: Influence on the growth and accumulation of dry matter of watermelon seedlings based on caragana-straw as nursery substrate in studies, it used to determine the feasibility of caragana-straw as nursery substrate, to provide theoretical basis for the development of caragana resource and follow-up industry. With “Zhuangmiao-2” nursery for the control matrix, through the matrix physical and chemical properties, seedling growth, dry matter accumulation, parameters of chlorophyll fluorescence induction dynamics and other indicators, effects of two seedlings were compared. The results showed that caragana straw and Zhuangmiao-2 were basically the same of the physical properties, available nutrient content of caragana straw was significantly greater than Zhuangmiao-2, plant height, stem diameter, leaf number, root length, shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, total fresh weight, total dry weight, root/shoot ratio of two seedlings were tends to be uniform, seedling index of caragana-straw seeding was higher than seedling index of Zhuangmiao-2 seeding 9.76%, at the same time the former light use efficiency slightly higher than the latter. Caragana-straw have potential to replace peat as nursery substrate raw material, which will be developed and utilized to be nursery substrate of industrial seedling in northwest arid regions.