Abstract: The present paper has concisely discussed the influence of particle size upon apprarent density, flow rate and compressibility of gas atomized 6-6-3 bronze powder. The more of fine particle (-320+400 mesh size) ie, the greater the apprarent density will be. The more of coarse particle is, thgreater he few rate will be. When the composition of fine powder is about 70%, the density of compressed unit reaches its summit.