Indoor air pollution is considered as one of the greatest risks to human health by many international health organizations. Therefore, there is a global trend to increase awareness among people of the importance of indoor plants as well as its important role in the purification of indoor air pollutants. So, this investigation was performed in Plexiglas chamber for evaluating the effects of foliar spraying of golden pothos and croton plants with non-enzymatic antioxidants: glutathione(GSH)and bilirubin(BI)at 300 mg L^-1 and 600mg L^-1 to increase their resistance and abilities to absorb formaldehyde and ammonia gases. Results showed that pothos and croton plants exposed to ammonia gas were extremely injured with a high number of dead leaves and decreased in fresh and dry weights as well as the total chlorophyll and carotenoids compared with the plants exposed to formaldehyde gas. GSH increased the total chlorophyll and carotenoids of pothos and croton under the formaldehyde gas. Treated pothos and croton plants with glutathione or bilirubin before exposure to the gases decreased the generation of reactive oxygen species(ROS),increase the guaiacol peroxidase and reduced polyphenol oxidase activities. Chloroplasts composition and stomatal index were injured with exposing croton and pothos plants to formaldehyde and ammonia gases with partially opening of stomata and moderately decrease the number of stomata. Pothos plants were greatly resistant and more growth efficiency when treated with BI at 600mgL^-1 before exposed to formaldehyde gas.In conclusion, spraying pothos and croton plants with GSH at 600mgL^-1 increased their resistance to formaldehyde and ammonia gases.