The flow and heat transfer visualization experiments have confirmed that pairs of longitudinal cellular vortices generated in the approaching jet collide intermittently with the heat transfer surfaces, crossing the geometrical stagnation line. A statistic analysis with conditional sampling applied to the near-wall turbulence measurements has explained successfully why the effect of longitudinal vortex pairs on the enhancement of jet impingement heat transfer becomes remarkable in the inner impingement region when a heat transfer surface is placed at 6 - 8 nozzle widths downstream of a nozzle exit. The heat transfer in the inner impingement region is enhanced owing to their surface renewal effect when they collide with the heat transfer surface. The heat transfer in the outer impingement region is controlled due to the surface renewal effect of large-scale turbulent eddies when they impinge there on the heat transfer surface.