Abstract: Studies on effect of cassava yield and soil physical and chemical properties by the different irrigation quota under mulched drip irrigation to provide scientific basis for popularization of mulched drip irrigation. The experiment using ‘Xinxuan 048’ (a cassava cultivar in Guangxi), with treatments of three irrigation quotas (450 m3/hm2, 750 m2/hm2, 1200 m3/hm3) and CK (0 m3/hm3) were studied the soil physical and chemical properties, cassava growth and yield. The results showed that the water content, total porosity, gas phase ratio, available nitrogen, phosphorus and potassium content of soil increased significantly with the increase of irrigation quota, and the height, stem diameter, yield and economic benefit of cassava also increased significantly. Compared with CK, the yield of 450 m3/hm2, 750 m3/hm2 and 1200 m3/hm2 increased respectively by 46.22%, 75.60% and 93.45%, and the economic benefit increased respectively by 19.24%, 26.46%, 61.07%. In short, the soil physical and chemical properties can be improved obviously by increasing irrigation quota under mulched drip irrigation, and cassava yield and economic benefits also can be improved. Among all the treatments, 1200 m3/hm2 treatment presents the optimal effects and is worth popularizing in cassava production.