Abstract: Displacement ventilation supplying air from the chairs and returning air from the top is used in the auditoriums of China National Grand Theater(CNGT).Studies on the airflow noise from the chair outlet are necessary.The precision method for reverberation chambers is used in the experiment to measure the sound power level(SPL) of airflow noise of two kinds of chair outlet under different conditions.The experimental result shows that there are no essential differences between two outlets in terms of air noise.They both meet the noise criterion for the CNGT.The experiment has removed an obstacle of HVAC noise attenuation design for CNGT.It may be used as a reference for other projects and similar chair outlets airflow noise research.