In this study, Pleurotus ostreatus were grown in bottles at temperatures set to 15°C, 20°C, and 25°C inside the cultivation room. Changes in temperature, CO2 concentration, and humidity inside the bottles were measured, and growth characteristics according to the temperature conditions were evaluated. CO2 concentration increased overall as the temperature increased and was particularly stable at 20°C, suggesting that 20°C is the optimal condition for the physiological respiration of P. ostreatus . While humidity was relatively constant at 15°C, it decreased over time at 20°C and was maintained at a stable level at 25°C, suggesting that water retention capacity may occur at high temperatures. As a result of the growth investigation, the yield per bottle and individual weight were the highest at 20°C, confirming that 20°C is the most suitable temperature condition for the growth of oyster mushrooms. At 25°C, the yield per bottle was maintained but the individual weight decreased and the color tended to change. These results suggest that the interaction between CO2 concentration, humidity, and temperature has a significant effect on the growth and quality of oyster mushrooms, and that it is effective to control the cultivation room temperature to 20°C for optimal growth.