A numerical study was carried out to examine the local heat transfer and flow situation around a square rod in a parallel plate duct as a spacer. Momentum and energy equations were solved by means of the pressure correction and the CONDIF methods. Effects of the space between the end of the rod and the opposite insulated wall were simultaneously estimated in the three-dimensional system. Three horseshoe vortexes were generated around the end of the rod at Re=1700. The characteristics of the local heat transfer and the flow behind the rod were elucidated.