The flow structure in the downstream region of the cooling fan has great impact on engine heat dissipation. An integrated PIV measurement system was designed and constructed to understand the flow field behind the cooling fan. In order to analyze the influence of interaction of different components on flow structure in downstream region, a series of experiments were conducted in four arrangements at three flow coefficients. The flow field was evaluated by velocity profile, vorticity, and turbulent intensity. These flow data reflect the effect of isolated components and their combinations quantitatively. This work provides useful information for engine cooling system design.