Abstract：In order to develop a seedling substrate mainly composed of decomposed rice husks，based on the determination of the physicochemical properties of single substrates such as decomposed rice husks，11 kinds of seedling formulas composed of decomposed rice husks were preliminarily determined according to the substrate physicochemical property model．The fruit vegetable seedling（tomato）and leaf vegetable seedling（lettuce）were used as test materials to further screen and determine the substrate formula suitable for the growth of vegetable seedlings．The results showed that the EC value and bulk density of decomposed rice husk were suitable，but the water holding pore was small，which was not suitable as a seedling substrate material alone．The composite desirability values of 11 substrate formulations predicted by the model were（0.91-0.98），which were all within the range of suitable indicators of seedling substrate，and the relative error between the measured values of physical and chemical properties of 11 substrate formulations and the predicted values of the model was small，ranging from 3.23% to 9.63%．The decomposed rice husk after mixing could meet the growth needs of vegetable seedling stage. Among them，the mixed substrate of decomposed rice husk∶vermiculite∶perlite with（6∶2∶2）had the best growth effect on tomato and lettuce，and the strong seedling index increased by 82.76% and 21.39% compared with that of the control，respectively，and the plant grows robustly．The prediction model of physical and chemical properties of substrate was feasible for the development of substrate．
