Abstract: In order to study the influence of sea surface temperature (SST) on the numerical simulation of low atmospheric ducts, the influence of different SST on the numerical simulation of lower atmospheric ducts over the South China Sea (SCS) was studied based on WRF model. The results show that the simulation of lower atmospheric ducts events is affected greatly by SST accuracy and the update frequency. The experiment scheme of the SST provided by US National Oceanic and Atmospheric Administration (NOAA) has the best simulation results with the accuracy of 68.2%, and its lowest mean error and standard deviation of duct-bottom heights are less than the other schemes, followed by climate forecast system reanalysis (CFSR) SST, which might be attributed to good numerical simulation of relative humidity and air temperature profiles. Besides those, nested grid pattern also affects the numerical simulation of atmospheric ducts. Using the best scheme, the duct characteristic parameters of the sub-grid simulation are more accurate, and the accuracy rate of the simulation and the duct probability increase by 11.8% and 10.4% respectively, with the false alarm rate decreased by 2.4%. This study provides technical support for accuracy numerical prediction of low atmospheric ducts over the South China Sea.