Abstract: In order to study the influence of emerged vegetation's bending deformation on flow resistance, open channel flume experiment was carried out to observe and analyze a single emerged vegetation's bending deformation and flow resistance under different flow conditions. The results showed that the flow resistance increased with the increase of vegetation's bending deformation when the vegetation changed from completely upright to curved and swaying emerged state. The flow resistance decreased significantly when vegetation changed from emerged state to submerged state. When the vegetation was in the submerged state of bending and swaying, the flow resistance would also increase with the aggravation of the vegetation's bending degree. However, when the bending deformation of vegetation increased to make the vegetation in a completely flattened state, the flow resistance would reduce. The research results are beneficial to balance the relationship between river ecological control and flood discharge in flood season.