In this project, a new structure of non isolated boost dc-dc converters based on voltage-lift technique is proposed. In comparison with conventional nonisolated boost dc-dc converters, the proposed converter generates higher voltage gain. In this, the relations between voltage and current of all elements in continuous conduction mode and discontinuous conduction mode are calculated as well as voltage gain in each mode. Then, the critical inductance and stress of switch current are extracted. Finally, the validity of given theories is examined by using the experimental results.