Abstract: The airflow domination relations between air ducts of ventilation network have significance in reasonable analysis of ventilation network.For a complex ventilation network system,sometimes it is difficult to obtain airflow domination relations between arbitrary two air ducts from ventilation network diagram directly,so the paper put forward conceptions of influence zone and dependent zone of arbitrary air duct of ventilation network,and pointed out that the conceptions can be used to analyze the airflow domination relations between arbitrary air ducts.It introduced a partition method of dependent zone and influence zone of each air duct in ventilation network and calculating algorithm of faith degree and dependence degree between arbitrary air ducts and used C# language to programme.Finally,a case was used to verify the validity of the algorithm discussed in the paper.