Due to the limitations of graphics’ capacity and bandwidth from main memory to video memory, a large amount of information in medical data has become the bottleneck in visualization. Compressed volume rendering, combining with volumetric compression and volume rendering, is one way to solve this problem. Hierarchical vector quantization (HVQ) and DXT1 are simple and effective, with great rendering performance, to meet the requirements of compressed volume rendering. DXT1 would be a useful attempt in visualization of medical data, because of very quick compressed and decompressed speed.