Pot experiment was conducted to study the effects of the application quantity of Sophora alopecuroides greenmanure on soil nutrientstatus，photosynthetic performance diurnalvariation，weight and quality of trellis -cultivated melon. The results showed that the application of Sophora alopecuroidesgreen manure significantly improved the soil nutrients， and it was more significantly to improve the content of available N of trellis-cultivated melon. The application of Sophora alopecuroidesgreen manure improved simultaneously photosynthetic capacity，and increased weight and improved quality of trellis-cultivated melon. The net photosynthetic rate(Pn)，stomatal conductance(Gs)，transpiration rate(Evap)，instantaneous water use efficiency(iWUE)of leaf of trellis-cultivated melon all diurnally varied with the bimodal curve. The photosynthetic performance of trellis-cultivated melon were the most significant integrated when the application of greenmanure was 200～ 400 g·plant -1(M2-M4).Correlation analysis showed that Pn and iWUE were the main photosynthetic factors influencing weight and quality of trellis-cultivated melon. The weight of trellis-cultivated melon was the highest in treatment M2 and increased by 48.5% compared with M0.The quality(crude protein，vitaminC，reducing sugar)of trellis-cultivated melon was the highest in treatment M3 and increased by40.50%，38.16% and37.30%，respectively，compared with M0. Ingeneral，the recommended application rate for Sophora alopecuroidesmanure is 200～ 300 g·plant -1.