Abstract: In this paper, a seamless terrain rendering algorithm based on GPU is proposed to solve the problem that the conventional multi-resolution terrain rendering methods are time-consuming and not suitable for processing T-crack. Firstly, the real-time Tessellation is introduced and the terrain mesh constructing is divided into two steps, i.e. conducting coarse granularity Tile mesh on CPU and subdividing fine granularity Patch mesh on GPU. Then, in order to take the range of visibility and the terrain roughness on terrain rendering into account simultaneously, in each Tile level of detail is selected according to LoD model based on the range of visibility and in each Patch level of subdivision is selected according to LoD model based on screen-space projection error. Thus, in this algorithm the selection of the terrain LoD is realized self-adaptively. Finally, by using C+ + language and DirectX 11 tools, a visual experiment system is developed and the experimental result shows that the multi-resolution terrain can be expressed seamlessly and self-adaptively ensuring the continuity of the terrain mesh. Moreover, our algorithm can significantly increase the terrain rendering efficiency through reasonable balance of CPU and GPU.