Based upon light scattering techniques, a turbidimetric spectrum method and corresponding inversion algorithm for particle size characterization are presented. Comprehensive theoretical analysis and computer simulation show that the presented method is capable of determining not only average particle diameter, but also particle size distribution in a very broad size range. In this paper the emphasis is on and limited to this method＇s applicability to fine particle size analysis, ranging from tens of nanometers to several micrometers. Experimental studies are carried out with submicron monodispersed lattices. The results of comparative measurements using the photon correlation spectrum (PCS) and presented turbidimetric spectrum method are also given. It shows that the agreement is good.