An efficient compressed volume rendering algorithm is presented. Firstly, the original volume data is compressed by a content-based classified hierarchical vector quantization algorithm. Secondly, the compressed volume data is then transferred to Graphic Processing Unit and decompressed in real time, subsequently, the decompressed data is rendered by a three-dimensional textures mapping method to accelerate the speed of rendering. Experimental results show that, in addition to reasonable fidelity and faster rendering speed, the presented algorithm can obtain multiple levels of detail on the off-the-shelf graphic hardware.