Several ornamental potted plant species have the ability to absorb pollutants and purify indoor air. The present study was aimed at to select best plant for pot transplantation in the cold areas of army installations. As diurnal variations in the temperature are high in these cold high altitude areas even in the indoor environment, plants were evaluated for their photosynthetic response under these conditions along with their oxygen releasing potential during light and dark conditions. Effect of temperature levels (10, 15, 20 and 25° C) and CO2levels (400, 420 and 450 ppm) were studied on net photosynthesis and transpiration rate in three indoor plants viz., spider plant (Chlorophytum comosum), dracaena (Dracaena fragrans) and snake plant (Sansevieria trifasciata). Decrease in photosynthetic as well as transpiration rate of these indoor plants was recorded with decrease in temperature from ambient (25°C) to 10°C. At 10°C, photosynthetic rate of Dracaena reduced to 1/7th of ambient whereas in case of snake and spider plants it was near to half only. Even though snake plant maintained the good photosynthetic rate (~5 umol/m2/s). Small increase in CO2 levels was not detrimental to photosynthetic efficiency of indoor plants even at temperatures lower than ambient. At 10°C, snake plant exhibited the maximum transpiration rate (0.163 mmol/m2/s). Among the three tested plants, Snake plant exhibited better oxygen releasing potential during both light and dark period.