Abstract: On the premise of meeting the requirements of the multi-stream heat transfer process，the optimal orga-
nization principle of the heat transfer processamong (1 + n) multistreams，which comes from one cold stream and multi hot streams or from one hot stream and multi cold streams，is discussed in this paper． Then，a functional analysisis conducted to solve the required minimum heat exchange area under a given entranspy dissipation． The results show that，when the process requirements are met and the product of the heat transfer temperature difference and the square root of heat transfer coefficient is kept uniform，the heat transfer process among (1 + n) multi streams shows the best performance with aminimum heat exchange area，and that the principle of keeping the temperature difference (Δt) uniform is not the best．

Key words: heat transfer, temperature difference, optimization