Circular　coil　made　from　cylindrical　solid　conductor　has　been　wildly　used　in　magnetic　resonance　wireless　power　transfer(WPT)　system.　As　key　components　of　system,　high　frequency　losses　of　coupling　coils　affects　the　system　efficiency　more　directly　when　the　operation　frequency　increase.　The　existing　analytical　methods　can＇t　meet　the　requirement　of　precision.　Moreover,　numerical　calculation　method　such　as　finite　element　method(FEM)　can　be　used　for　calculating　high　frequency　losses　of　multi-turn　coil,　however,　it＇s　time-consuming　and　high　cost.　After　fully　analyzed　skin　effect　and　proximity　effect　of　helix　coil,　this　paper　presents　a　new　analytic　method　for　evaluating　high　frequency　losses　of　multi-turn　cylindrical　solid　coil.　It　is　fix　all　cylindrical　solid　or　Litz　wire　coil　which　is　shaped　as　helix,　spiral　or　multi-layer,　and　so　on.　Quality　factor　optimization　by　using　the　analytic　method　has　been　done　and　proved　high　precision　and　much　better　computation　efficiency　compared　with　existing　methods.　Finally,　experiment　for　verification　is　done　and　the　conclusions　have　been　got.　©,　2015,　Chinese　Machine　Press.　All　right　reserved.