[Objective] The ecological adaptability of trees in the water-level-fluctuation zone of reservoirs in the parallel flow area of three rivers was determined in order to provide a scientific basis for the selection of dominant afforestation species for ecological restoration in this area. [Methods] Seedlings of Taxodium hybrid, Pterocarya stenoptera, Salix americana, and Taxodium ascendens were selected for a small-scale afforestation experiment in the fluctuating zone of the Huangdeng Reservoir on the Lancang River. The survival rate and basic growth of trees were observed, and the crown shape and structure, shoot and branch characteristics, and biomass were observed two years after transplanting. [Results] At the initial stage of transplanting, the survival rate of three of the tree species (Taxodium hybrid, Pterocarya stenoptera, Taxodium ascendens) decreased significantly with the increase of flooding and drying times in the drawdown zone. Two years after transplanting, the survival rates of the four tree species followed the order of Salix americana (100%)＞Taxodium ascendens (48.78%)＞Pterocarya stenoptera (40.19%)＞Taxodium hybrid (32.86%). The growth of Salix americana was significantly greater than that of the other three species, and the tree height and crown width of Pterocarya stenoptera and Taxodium hybrid “zhongshanshan” fir decreased due to dying and dead branches. The total biomass of Salix americana and the biomass of each constituent organ were significantly greater than those of the other three tree species, and the proportion of each constituent organ to the total biomass was relatively balanced, with the trunk being the main part, and the leaves and branches of Taxodium hybrid accounting for the smallest proportion of the total biomass. [Conclusion] The suitability of the four tree species in the fluctuating zone of the Huangdeng Reservoir of the Lancang River followed the order of Salix americana＞Taxodium ascendens＞Pterocarya stenoptera＞Taxodium hybrid. The survival rate of Salix americana was 100% two years after transplanting. It should be considered the recommended tree species for the restoration of fluctuating vegetation in the three parallel rivers reservoir area.