Branch network is a kind of structure that exists widely in nature, it can be found in diverse engineering systems from underground geothermal mining to fuel cell. In this paper, we study the convective heat transfer property in a basic unit of branch network. Based on the fully developed convective heat transfer model for laminar flow in a pipe, the theoretical expression of heat transfer rate is obtained. The effect of symmetry of branches on the heat transfer rate varies with the trunk diameter of the branched structure, and the effect of symmetry branched structure is not always the favorable. The heat transfer rate increases with the increase of pressure drop, trunk diameter and temperature difference, whereas the heat transfer rate decreases with the increase of the length of the branched structure. The presented work sheds some light on diverse applications of branch network for engineering system design. (C) 2017 Elsevier Ltd. All rights reserved.