Abstract: A numerical simulation was performed to study the laminar flow field structure of the submerged circular jets and single phase convective heat transfer at the impinging stagnation point. The factors considered are jet velocity, nozzle diameter, nozzle-to-(impinging) plate spacing and the diameter ratio of the heat transfer surface to nozzle. The numerical results showed that the location of vortex on the impigning plate was getting far from symmetry axis with the increasing of the exit Re number. For the fully developed tubular nozzle the stagnation point heat transfer coefficient enhanced with the elevating of exit Re and the decreasing of nozzle diameter, is independent of the diameter ratio of the heat transfer surface to nozzle and presented peak value in 5<z / d<9.