Since volume rendering needs a lot of computation time and memory space, many researches have been suggested for accelerating rendering or reducing data size using compression techniques. However, there is little progress in a research for accomplishing these goals. This paper presents an efficient wavelet-based compression method providing fast visualization of large volume data, which is divided into individual blocks with regular resolution. Wavelet transformed block is run-length encoded in accordance with the reconstruction order resulting in a fairly good compression ratio and fast reconstruction. A cache data structure is designed to speed up the reconstruction, and an adaptive compression scheme is proposed to produce a higher quality rendered image. The compression method proposed here is combined with several accelerated volume rendering algorithms, such as brute-force volume rendering with min-max table and Lacroute's shear-warp factorization. Experimental results have shown the space requirement to be about 1/27 and the rendering time to be about 3 seconds for data sets while preserving the quality of an image much like using the original data.