Abstract: The setting up of temperature autocontrol system for the Coudé room of the 1.2m telescope at Yunnan Observatory and realizing the airflow autocirculation,purified the air,keeping the temperature in the Coudé room constantly by autocontrcl the heater,and then keeping the optical system in the best condition are introduced in this paper.The autocontrol system is designed and developed at the basis of having only the air circulator and the heater controled by hand.