Of late in Korea, as concern about well-being has risen, there has appeared a movement to make clean air, and improve residential environment using already purified air. To reduce indoor air pollution, air is ventilated by an air-conditioner, and contaminants are controlled by many means. This study made use of an air purifying plant for indoor setting to create pleasant air not by mechanical way, but natural way. The effect was confirmed with that experiment, on which three plants(Aglaonema, Pachira aquatica, Ficus benjamiana) having good effect were selected. The initial experiment to the three kinds of plants was conducted in order to reduce the concentration reduction of VOCs produced in autumn. The concentration of Benzene, Toluene, Ethylbenzene, Xylene, Stylene, Formaldehyde were monitored, since they were known as most toxic materials. In the experiment regarding planting and growing amount, the plants were divided by 10% and 5% of the experiment space, and that to the placement of planting and growing, sunny spot placement, and scattered placement were measured respectively. The measurement was made on the apartment measuring method at three in the afternoon for three days in a row after 5 hour closed state for 5 hours after ventilation for 30 minutes in the morning. The experiment findings are as follows. (1) In decrease of Formaldehyde, the effect was the best at set-up in the change of planting volume and arrangement, and in decrease of Toluene, the decrease effect was excellent at Pachira aquatica set-up. (2) The plating and growing amount experiment was most effective with Pachira aquatica set up by 10% of the experiment room space. (3) In the plating and growing placement experiment, the sunny-spot placement of Pachira aquatica was most effective, and in reduction of Formaldehyde, Aglaonema brevispathum was effective.