The　advantages　of　photovoltaic　(PV)　power　generation　include　no　fuel　cost　and　abundance　of　sunlight.　For　the　grid-connected　PV　inverter　systems,　the　efficiency　is　always　an　important　issue.　At　the　PV　panel　side,　a　DC/DC　converter　with　maximum　power　point　tracking　operation　is　always　used　to　improve　power　generation　of　the　system.　Further,　at　the　grid-connected　inverter　side,　the　generated　active　power　is　proportional　to　the　power　generation　efficiency.　Therefore,　the　grid　current　is　expected　to　be　in　phase　with　the　grid　voltage　and　the　current　harmonics　must　be　low　to　avoid　excessive　losses.　In　this　paper,　a　switching　strategy　is　proposed　to　generate　the　grid　current　with　low　harmonics.　Both　baseband　harmonics　and　the　side-band　harmonics　are　considered.　In　the　simulation,　it　is　shown　that　a　79.5%　reduction　of　baseband　harmonics　and　a　34%　reduction　of　the　total　harmonies　distortion　are　achieved　comparing　with　the　conventional　switching　strategy.　The　direct　advantage　is　the　improvement　of　the　system　efficiency.