Abstract: Due to the chemical toxicity and radioactivity (α emitter), ²²⁶Ra is one of the most important radionuclide for the environmental radioactivity monitoring. Herein, a rapid method for the determination of ²²⁶Ra in natural freshwaters by inductively coupled plasma mass spectrometry (ICP-MS) was established. In general, after the pre-concentration of water sample from 500 mL to 15 mL, separation of Ra from these potential interfering elements (i.e. Ca, K, Mg, Na, Sr and Ba ) was achieved using AG 50W-X8 ion exchange resins and Sr-resin, followed by the ICP-MS measurement. Results of four natural freshwater samples show that the ²²⁶Ra recovery range from 90% to 95%, and the detection limit of the methodology is determined to be 0.04 pg/L (1.46 mBq/L, n=10) for 500 mL sample. Compared to conventional radiometric techniques, the as-established method greatly shortens the analytical time for ²²⁶Ra determination (about 10 h), providing a rapid and reliable way for the determination of ²²⁶Ra in daily monitoring and emergency response.