Abstract: In response to the extremely hot-humid weather in the South China Sea area，a novel 1-D transient heat and moisture coupled transfer model (LPc-model) for building walls was developed by selecting capillary pressure logarithm as the moisture driving potential and the outdoor and indoor air parameters as the boundary conditions and taking the air infiltration into account． HAMSTAD Benchmark 2，3 were used to verify the accuracy of the model．The good agreements between the calculated results and benchmark test results indicate that the model can be used to calculate the heat and moisture coupled transfer including air infiltration inside the wall． The applicability，accu-racy，and calculation efficiency of the new model was compared with the existing capillary pressure model (Pc-mo-del) and relative humidity model (ＲH-model) under benchmark test condition and a realistic condition． The results show that only the LPc-model and ＲH-model can calculate the two benchmark tests accurately，LPc-model has the fastest convergence speed，and Pc-model cannot completely calculate the benchmark 3． Under real weather conditions，only LPc-model and ＲH-model can complete the calculation，and ＲH-model has a faster convergence speed and more narrower fluctuation in the results．

Key words: building wall, mass transfer driving potential, capillary pressure, coupled heat and moisture transfer, air infiltration