Abstract: A laser-scattering method for the determination of particle size distribution of pharmaceutical suspension intended for intravenous use is proposed. By this method, after the suspension had been aerosolized, it was passed into the scattering cavity of Guang Ming dust particle counter (model JDG-101, made in China), the number of aerosol particles were counted automatically in certain size ranges (e. g. 0.3 μm, 0.5 μm, 1.0 μm, 2.0 μm, 5.0 μm).In order to prove the validity of our results, an imported dust particle counter apparatus and other three detecting methods were employed for comparison. It was found that all results obtained by the above mentioned apparatus and methods were in considerable conformity with those obtained by the proposed laser-scattering method using the apparatus of our own make.