Abstract: A novel tube circuit optimization approach for fin-and-tube heat exchanger was presented by developing a particular genetic coding method and genetic operators.A case study was performed on a practical heat exchanger.The optimization objective of the case was to obtain the shortest joint tube length of the tube circuit with the constraint conditions of satisfying the designed heat exchange capacity and the convenience of manufacture.Optimization result showed that the designed algorithm could converge within 5 h and the total joint tube length decreased by 25% after optimization.