A　novel　zero-voltage　and　zero-current　transition　dc-dc　converter　is　presented　in　the　paper.　Soft-switching　of　the　main　switch　and　auxiliary　switches　can　be　achieved　by　using　two　auxiliary　resonant　networks.　The　proposed　converter　has　such　advantages　as　zero-voltage　and　zero-current　turn-on　and　zero-voltage　and　zero-current　turn-off　for　the　main　switch　without　increasing　voltage　and　current　stress,　zero-current　turn-on　and　turn-off　for　auxiliary　switches.　It　is　very　attractive　for　high　power　application　where　igbt　is　predominantly　used　as　the　power　switches.　Its　operation　principle　is　analyzed　through　its　application　to　the　boost　converter.　The　condition　of　soft-switching　and　the　design　considerations　are　analyzed　in　detail.　The　novel　soft-switching　cell　can　be　also　used　in　other　basic　dc-dc　converters.　Some　experimental　measurements　are　used　to　verify　the　theoretical　prediction　and　analytical　discussion.