A　high　efficiency　Zero-voltage-switching　three　Level　Boost　Converter　for　Power　Factor　Pre-regulator　is　proposed　in　this　paper.　The　topology　can　perform　ZVS　in　the　main　switches　and　the　passive　switches,　and　zero-current　switching　in　the　auxiliary　switch.　Furthermore,　soft　commutation　of　the　main　switch　is　achieved　without　additional　current　stress　by　the　presented　ZVS-PWM　auxiliary　circuit.　A　significant　reduction　in　the　conduction　losses　is　achieved,　since　the　circulating　current　for　the　soft　switching　flows　only　through　the　auxiliary　circuit　and　a　minimum　number　of　switching　devices　are　involved　in　the　circulating　current　path,　and　the　proposed　rectifier　is　suit　for　low　line　voltage　and　high　power　applications.　A　prototype　rated　at　600W,　operating　50kHz,　with　an　input　ac　voltage　of　120　Vrms　and　an　output　voltage　of　400　Vdc　has　been　implemented　in　the　laboratory.　An　efficiency　up　to　97%　and　power　factor　over　0.99　has　been　measured.　©2007　IEEE.