Abstract: This study aims at investigating the navigable flow condition of mountain reservoir on Jinsha River through three-dimensional (3-D) numerical simulation. The non-structural grids were employed for terrain representation and various discharges were adopted as the incoming boundary conditions. Taking Panzhihua reach as an example, we preferentially simulated the hydrodynamics characteristics under certain inflow boundary conditions, mainly focusing on the distribution of water depth, velocity, flow field and circulating flow. Furtherly, the probable obstructing navigation areas were analyzed. The results revealed that the water depth increased along the river, basically meeting navigation demand of three-level channel. While under some inflow conditions, there exists obstructing navigation areas in the local narrow channel, sudden-expansion channel and bend channel. The research results can provide technical reference to the joint operation of cascade reservoirs on the Jinsha River.