Abstract: In order to test the function of ventilation system of chambers. Measurement of harmful gas in chambers loaded with pigs or chickens was taken after 5 days or 11 days working continually. The concentration of ammonia and carbon dioxide in chambers were 11.3～19.7mL/m^３ and 890～1 400 mL/m^３ respectively. The measuring values were all below the standard values of animal health. But it is noticeable that the concentration of ammonia in chamber of chicken before clearing excreta in the morning and of carbon dioxide in the chamber of pigs were higher, approching to upper limit of standard of animal health.