A mathematical model has been presented for simulating heat transfer in a hot dry rock with a complex-shaped fracture network. In this model, the energy equation in the fracture is expressed in terms of the finite difference approach and the matrix is expressed in terms of the finite element approach. From the results calculated by this model the following conclusions are obtained: 1. The model is valid to the simulation of fluid flow and heat transfer in the complex-shaped fracture network.2. The shape of fracture network, the number of fractures and the injection rate of water into an injection well affect both the temperature of fluid from a production well and the cumulative recovery factor of heat from the hot dry rock.3. The injection rate of water may have to be determined by considering both the period of heat recovery and the available temperature of production fluid. Key words: hot dry rock, fracture network, heat transfer, finite difference approach, finite element approach