The aggregation and fractal structure of mixed metal hydroxides ( MMH ) agglomerates with increasing ionic strength have been studied by dynamic light scattering ( DLS ) and SEM techniques. The experiments indicate that the MMH agglomerates have two different structures in RLA regime and DLA regime, and also give the proof that the transition region between RLA and DLA may occur. The aggregation and fractal structure of mixed metal hydroxides (MMH) agglomerates with increasing ionic strength have been studied by dynamic light scattering (DLS) and SEM techniques. The experiments indicate that the MMH agglomerates have two different structures in RLA regime and DLA regime, and also give the proof that the transition region between RLA and DLA may occur.