A revised method based on the dynamic programming is proposed for the operational planning of heat supply systems with storage unitS. The on/off status of operation and heat flow rates of heat producing and conversion equipment as well as the heat levels of storage units are determined to minimize the operational cost and satisfy heat demands for a period considered. This optimization problem is formulated as a mixed-integer linear programming one, and a method of solving it efficiently is presented: (a) the dynamic programming is used as a basic solution algorithm to determine the optimal paths for discretized heat storage levels, (b) the branch and bound algorithm is revised to obtain aI1 the candidates for storage levels only by one series of branch and bound operations, and (c) some rules based on upper and lower bounds for the objective function are adopted to reduce the number of candidates for storage levels. A case study is carried out on the operational planning of a heat pump system with a storage tank to ascertain the validity and effectiveness of the proposed method.