Abstract: In order to measure the size and volume concentration of particles of several microns accurately and rapidly, an experimental device was designed with a linear array CCD as detector, based on the Fraunhofer diffraction. The Shifrin-transform method was adopted to analyze the particle size distribution, peak value, and mean size and volume concentration. Compared to the conventional Swithenbank conversion method which adopted the self-scanned photodiode array to achieve particle size distribution, the method doesnt need to have precognition information such as upper and low limit as well as interval separation of the particle, and etc. The agreement has been obtained between theory and experiment. The experimental results show that higher accuracy in the measurement of particle size and volume concentration is achieved.