Traditional monitoring on water quality is mainly carried according to the instantaneous concentration of pollutants in river, which is time consuming and labor cost. A method based on reuse of ion-exchange resin capsules was evaluated for continuously adsorbing ions in the Longhongjian stream discharged into the West Lake of Hangzhou City. Results showed that the recovery rates of reuse-resin capsule were greater than 95.91% for both NO₃^- and PO₄^3- , but the differences among treatments were not significant. The recovery rate of reuse-resin capsule for NH₄⁺ was greater than 100% in low concentration and 90% in high concentration. Significant correlations existed between resin capsule cumulative adsorption(RAQ) value and flow in all kinds of ions(R²=0.59, 0.47 and 0.50, respectively, p<0.05). Moreover, there was a significant positive correlation(R²=0.46, p<0.05) between RAQ of NO₃^--N and concentration of NO₃^--N and water flow, indicating that resin capsules can be used in water monitoring of nitrogen and phosphorus, especially NO₃^--N.