Abstract: Natural ventilation is an effective measure to enhance indoor quality and to improve the comfort of human thermal. Taking Huizhou traditional dwelling as the investigated building, multi-zone flow analysis software CONTAM was employed to simulate the daytime and nighttime natural ventilation network of the traditional dwelling in summer to obtain the rule of air change rate with different driving force. The results show that daytime natural ventilation network is different from that of nighttime in the dwelling; during daytime, cross ventilation throughout the hall is produced, and the bedroom occurs single-side ventilation; at night the bedroom and hall both generate buoyancy-driven natural ventilation, and natural ventilation at night is strengthened for the existence of wind-driven natural ventilation at the same time; during daytime, the air change rate of the bedroom, hall, patio is 9.89, 15.25, 50.01 h^-1, while the air change rate of the bedroom, hall, patio is 1.74, 7.58, 8.41 h^-1 during nighttime, respectively, and the air change rate of each zone satisfies the minimum fresh air ventilation requirement. Moreover, the bedroom is only affected by thermal pressure regardless whether daytime or nighttime, while the hall and the patio is affected primarily by wind pressure during daytime, and is mainly driven by thermal pressure during nighttime.