Clusters in aqueous solutions of KCl and sugar were observed by a laser scattering ultra-microscope (LSUM), which provided direct evidence of the existence of clusters. The size, numerical density and electrical features of clusters in saturated solutions of KCl and KDP were characterized hy varied light scattering methods, The numerical density of clusters decreased with the size increment and most of the clusters were much smaller than 100 nm in diameter. The average size was about 1.3 times as large as their unit cells of KDP and KCl crystals in the saturated solutions after filtration with a 450 nm pore filter. These large clusters of KDP and KCl were uncharged molecular particles,