<p>Impulse waves generated by partially submerged landslides usually occur in mountain reservoirs, which may endanger human lives and the safe operation of the reservoir. The objective of this study is to investigate the characteristics of waves generated by partially submerged landslides using a large-scale physical similarity model based on the Rongsong deposit. River cobbles are used to replicate the landslide body, and three sliding velocities are achieved by changing the material of the sliding surface. The results show that wave heights are significantly influenced by topographical features of the river. The second wave is higher than the leading wave upon generation, but the crest of the third wave is the highest at the entrance of the river channel. The waves running up at the dam surface reflect and superimpose with the waves propagating from the river, which could lead to higher runup height on the dam. There may be a great risk in considering only the leading wave for waves generated by a partially submerged landslide. Based on the topographic characteristics of V-shaped channels, the effective still water depth is proposed to obtain an accurate celerity. The results are useful in understanding interactions between waves generated by partially submerged landslide and dam in mountain reservoirs, and can provide an important reference for the treatment of potential landslides and the design of dams.</p>