In the present paper a minimal spanning forest algorithm is employed for the location of heat source and design of distribution network instead of the widely-used 0,1 mixed programming. "Its main points aret 1. The weight of branch is composed of the cost of heat source and the cost of network; 2. For a current forest, only weight of the edge which are directly connected with the current forest is evaluted.As the forest expands,the range,in which the weight of edge is evaluated, also extends. In addition, the programming is simple in principle and short in operating time.