TheAmericataxTaxisthesourceofAmericanfiscalfunds,alsoisanimportantpartthatmaintainthenormaleconomyoperation.TheratiooftaxintheGDPfluctuateswitheconomicfallandrisetheoutbreakofthewar,thegovernment'salternationandlegislativechanges.Sincethe1960s,TheratiooffederaltaxintheGDPis18.2%onaverage.Duringthisperiod,Theratioin2000fiscalyearis20.8%,whichisthehighestratiosinceSinceworldwarII,andbecauseoftheeconomicdownturnandpolicyinfluence(suchastaxcuts),infiscalyear2004,thisproportionfellto16.5%,thehistoricallows.Afterhundredsofyearscontinuousrevisionandupdation,itmaybesaidthatAmerica'staxsystemisveryperfect.Ingeneral,Americantaxcanbedividedintothefollowingcategories:federaltax,statetaxandlocaltax;seeingfromthecategoriesoftaxes,apersonalincometax,corporateincometax,socialsecuritywelfaresecuritytaxandhealthmedicaltaxes,salestax,propertytax,realestatetax,inheritancetaxandgifttax,consumptiontax,etc.;Seeingfromtaxrateanddividedintosingletaxrates,progressivetaxrateandLapsetaxrate;InthetaxonthemeasurementdividedintospecificdutiesandADvaloremtax.ThenIintroducebrieflytheAmericatax.ThecharacteristicsofAmerica'staxpolicyis”RobinHood”.Secondly,IntheUnitedStatesthefamilyasaunitpaytax.Thirdly,theUnitedStatestaxreliefprogramalsoreflectsthepolicyof"consideration"and"pragmatism".Fourth,theUnitedStateshasallkindsofconsumptiontax,whentheygotorestaurant,gotoshopping,buyaticketandsoonall,theyhavetopaytax.