Abstract: "U" style ventilation mode is used on 8303 working face of Ganzhuang coal mine.The pressure differences in both ends of the gob air-leaking passage create the gas emission from the interior gob,which leads to the gas accumulation in the upper corner of the working face.Aiming at the problem,through analyzing gas sources and concentration overrun reasons,the proposal of controlling upper corner gas is proposed by using pressure balancing ventilation technology.It is known from the gas concentration changing situations that pressure balancing ventilation achieved good results in upper corner gas control of 8303 working face.