This paper presents the analysis and design of a non-isolated two-phase interleaved boost dc-dc converters in discontinuous-current modes (DCM). This topology in the DCM can easily achieve a higher voltage gain with a reasonable duty ratio compared to continuous-current modes (CCM) while having continuous input current and low stress on components. Operating the converter in DCM requires to use a smaller inductor, which will reduce the size and weight of the topology further. These important features will make this topology a preferred choice for many applications such as PV, Fuel cells, X-ray, etc. The operating principles of the topology and equations of the voltage gain and other vital parameters are explained and given in this paper. Moreover, the topology was simulated to convert 20 V to the output voltage of 400 V. Finally, a 200-W hardware prototype of the topology was implemented in a laboratory to verify the analysis of the converter in DCM.