Abstract: In an environment with different substrate moistures 100% (W₁), 80% (W₂), 60% (W₃) and 40% (W₄) of moisture capacity of substrate and illumination levels 100% (L₁), 70% (L₂), 40% (L₃) of natural light intensity interaction, the growth, physiological and biochemical properties of muskmelon seedling were investigated using netted muskmelon “Xiyuyihao” as material. Results show that seedling growth is significantly influenced by substrate moisture and light intensity, with 80% substrate moisture and 100% light intensity presenting the strongest growth vigor in greenhouse. Light intensity has a significant effect on soluble sugar content. Only under 100% light intensity does substrate moisture significantly influence soluble sugar content. Under three different illumination levels, soluble protein and free proline contents obviously increase with reduced substrate moisture. When the substrate moisture is the same, the effect of light intensity is relatively less. In all the treatments, W₂L₁ exhibits the lowest SOD and POD activity, and simultaneously showing a low CAT activity. While W₂L₁ has the minimum, W₄L₃ has the maximum MDA content.