The energy consumption of ceiling radiant cooling combined with air supply system of different cooling load sharing rates (CLSRs) in residential buildings in summer was analyzed. Two air supply strategies were considered, including the all outdoor air ventilation strategy and the primary return air ventilation strategy. The appropriate CLSR range within the energy saving standard was discussed, and the appropriate ventilation strategies which could reduce system energy consumption effectively in summer were also analyzed. The results show that the energy consumption of the composite system reduces when the sensible heat load sharing rate (SHLSR) of the radiant terminal device (RTD) increases. In the all outdoor air ventilation strategy, when omega(c) (the SHLSR of RTD) varies in the range 45-100%, the system energy consumption can be controlled within the energy saving standard, and taking the total heat recovery unit is an effective way to reduce energy consumption of outdoor air handling. In the primary return air ventilation strategy, omega(c) = 0.5 should be taken as a critical point. When omega(c) < 0.5. the primary return air ventilation strategy is recommended to reduce system energy consumption; when omega(c) > 0.5, the all outdoor air ventilation strategy is suggested. (C) 2012 Elsevier B.V. All rights reserved.