Abstract: Internal solitary waves (ISWs) with large amplitudes frequently occur in the Andaman Sea, and they have important impacts on marine ecology and offshore activities. In this work, the generation and propagation of internal solitary waves in the southern Andaman Sea are numerically studied using the non-hydrostatic MIT general circulation model (MITgcm). Remote sensing images are used to validate the simulation results. First, we investigate the source and propagation speed of the ISWs in the southern Andaman Sea based on the numerical simulation results. The source sites of the ISWs are mainly in four areas of the Andaman Sea: the Great Channel, the channel between the Nicobar Islands, the shallow water channel at the northern continental slope of Sumatra Island, and the ridge near the continental slope of northeastern Sumatra Island. The sources are consistent with that obtained from the remote sensing images. The generation of ISWs is subject to the baroclinic tide regime. Second, we designed sensitivity experiments to investigate the impacts of 2D model effect, strength of the background tidal current and structure of topography on the generation and propagation of the ISWs in the southern Andaman Sea. The simulation properly reproduces that the propagation speed of the ISWs in the southern Andaman Sea is between 2.3 and 2.6 m/s, and the maximum amplitude up to 70 m. By increasing the intensity of the background currents in the numerical model, the number of ISWs in each wave packets increases, wave amplitudes become larger and the time interval between adjacent waves shortens. By modifying the local topography in the numerical model, we find that double-ridge structure can increase the amplitude and number of the ISWs by compared with a single ridge topography.