Abstract: Pot trials were conducted to investigate the effects of single basal application of controlled-release fertilizers(CRFs) on root activity and nutrient absorption of rice.The results indicated that single basal application of BNCRF and BRCU significantly increased root bleeding intensity during early to mid growth stages of rice,and amino acid-N concentration of root bleeding at all growth stages,as compared with split application of rice specific fertilizer(SNRSF) at the same nutrient rate.In addition,treatments of the two CRFs significantly increased both total root absorption area and root active absorption area.Regarding to nutrient absorption,BNCRF significantly enhanced absorption rates of N and P in both early and mid stages,while BRCU enhanced absorption at mid stage.The BLCRF treatment with lower K ratio had relatively lower root activity, smaller root absorption area at early stage,which was enhanced at mid and late stages,resulting in N and P absorption rates similar to treatment of SNRSF.These results indicated that single basal application of CRFs could enhance the activity of root system,benefit nutrient absorption at mid stages,thus improving physiological function of rice root system.