Many application calls for high step-up dc-dc converter that do not require isolation. To obtain a high step-up gain with high efficiency in nonisolated application, a high step-up technique based on the stacking basic boost converter elements is introduced in this paper. In this converter a high step-up conversion ratio and distributed voltage stress can be achieve and reduce reverse recovery on diodes. Based on a conventional quadratics boost converter, the derived converter satisfies all there feature, which make is suitable for high step-up application. The operational principle and characteristics of proposed converter are presented, and verified experimentally with a 1 kW, 100 V input, 400 V output prototype converter.