The objective of this study was to develop and verify an effective vortex typed nonfilter nonpoint source pollution reduction device. To verify this pollution reduction device, a total of twelves scenarios (three rainfall intensities×two states×two steps) of experiments were conducted using pollutants. First, simulated inflow (rainfall intensity 2.5 mm/hr: 0.00152 m3/s, rainfall intensity 3.395 mm/hr: 0.00206 m3/s, rainfall intensity 6.870 mm/hr: 0.00326 m3/s) was calculated. Second, pollutants (mixture of 25% of four particle sizes) were selected and injected. Third, pollutant removal efficiencies of this device at its initial state and operating states were measured. As a result of analysis based on rainfall intensity, the concentration of pollutants was decreased by the device at initial and operating states at all rainfall intensities. Its pollutant removal efficiency was more than 80%, the standard set by the Ministry of Environment. Its pollutant removal efficiency was gradually increased over time, reaching approximately 90%. Its pollutant removal efficiency was higher in its operating state than that in its initial state. Therefore, nonpoint source pollutants can be effectively removed by this vortex typed nonpoint source pollution reduction device developed in this study.