Abstract: A dust neutralizing and flocculating system used in an air cleaning system for removing contaminants contained in indoor air including a radio frequency generating electrode and an ion generating electrode. Fine particles passing through a moderately efficient filter equipped in the air cleaning system sequentially pass through the radio frequency generating electrode and ion generating electrode. The fine particles are dipolarly magnetized while passing through the radio frequency generating electrode, thereby exhibiting an increased inter-particles attraction. The ion generating electrode adds cations and anions to the fine particles, thereby promoting the flocculation of the fine particles circulating in the room installed with the air cleaning system. By virtue of the promoted flocculations, the particle size of the particles circulating in the room increases. The particles with an increased size are secondarily removed by the filter.