Nowadays, chaos generators of multi-scroll chaotic attractors have received considerable attention to model, simulate, design and use them in engineering applications. The interest is in both theoretical and practical issues, while a direct application is in the eld of chaotic synchronization to implement private communication schemes, where the condential information being transmitted is embedded into a chaotic signal by direct modulation, masking, or another technique. At the receiver end, if chaotic synchronization is perfectly achieved, one can extract the hidden information from the transmitted signal. In this Thesis, two multi-scroll chaotic oscillators are synchronized. The synchronization is performed by generalized Hamiltonian forms and observer approach from nonlinear control theory.