To solve the layout and height adjustment of shore beacon suitable for large variation of water level in the Three Gorges reservoir area，a novel type of self-floating lift navigation mark is proposed. Aiming at the influence of structural design and environmental load on motion characteristics of this navigation mark，a 3-D hydrodynamic model based on MOSES（multi-operational structural engineering simulator）is developed，and the heave responses of the structure under wave action and combined action of wind，wave and current are studied with different drafts and depths. The results show：1）Improving the motion responses by the increase of draft is limited. The motion characteristics of the structure are optimal at 1.0 m draft.2）The greater the water depth，the better the motion characteristics. 3）The motion characteristics under the combined action of wind，wave and current are better than those under the action of wave.