In this paper, a new nonisolated high step-up dc-dc converter is proposed. Active-passive inductor cells (APICs) are used to extend the topology. The ability to achieve high gains is the main merit of the proposed topology. The proposed converter operates based on parallel charging and series discharging of the inductors. The converter also achieves high step-up voltage gain with appropriate duty cycle and low voltage and current stress on the power switches and diodes. The proposed converter is analyzed in operation modes. The main parameters of the converter such as voltage gain, voltage stress of semi-conductor devices are calculated to compare with other structures. Considering the output voltage ripple and filter size, the proposed converter is designed. Moreover, the losses and efficiency of the converter are calculated. The performance of the proposed converter is validated by experimental results.