Abstract: The effects of bio-organic fertilizer on plants growth and root tubers yield of cassava were studied in this experiment, of which the cassava variety FUXUAN01 and the bio-organic fertilizer produced by LIDA company were used as materials. The results showed that the effects of bio-organic fertilizer treatments on the plant height, the stem diameter and the leaf area index of cassava showed more or less promoting effect. At the late period, the plant height, the stem diameter and the leaf area index of the bio-organic fertilizer treatments were higher than that of the control. Besides, the bio-organic fertilizer treatments increased the root tubers yield. The root tubers yield of the 750kg/hm2 bio-organic fertilizer treatment was the highest which increased the root tubers yield by 70.88% higher than that of the control. The 450kg/hm2，600kg/hm2，900kg/hm2 bio-organic fertilizer treatments increased the root tubers yield by 5.06%, 49.36% and 20.88% respectively higher than that of the control.