Objectives:TounderstandtrendsandepidemiologicalfeaturesofsyphilisovertherecentyearsinChinaandprovideascientificbasisfordevelopingpreventionstrategies.Methods:From1985to2000,syphiliscase-reportingdatacollectedfromallprovinces,autonomousregionsandmunicipalitieswereanalyzedbyapplyingepidemiologicalmethods.Results:(1)Epidemictrends:syphilisincidencehassteadilyriseninChinafrom1985to2000,especiallyafter1993,whenitassumedanexponentialgrowthpattern.80,406casesofsyphiliswerereportedinthecountryin1999,whichwasalmost40timesthenumberreportedin1993.Duringtheperiodof1993-1999,theannualaveragegrowthofthesyphilisincidenceratewas83.55%.Perhapsduetoarecentnationallawenforeementcampaign,thenumberofreportedsyphiliscasesdroppedslightlyin2000.(2)Geographicaldistribution:Syphilisspreadfromcoastal,""open""cities(especiallysomecitiesinFujianprovince)toinlandurbanareas,thentoruralareas.RegionswithahighincidencerateofsyphilisinChinaweretheMinjiang,Yangtze,andZhujiangRiverDeltas,BeijingandTianjinmunicipalities,andNortheastChina.Therewasasignificantdifferenceofsyphilisincidenceratesandgrowthratesbetweentheseareas.Aseriousepidemicoccurredinsomeareas,withanincidenceratereachingover200casesoutof100,000.(3)Populationdistribution:theratioofmaleandfemalecasesgraduallychangedfrom1.57:1in1993to1.02:1in2000.Theratewasthehighestinthe20-29agegroupandthelowestin10-14agegroup.Agreatdifferenceexistedinprevalencebetweendifferentpopulationgroupsanddifferentareas,andsomeareaswithseriousepidemicshadhighprevalenceratesevenamoungthegeneralpopulation.(4)Clinicalstageofsyphilis:Primaryandsecondarysyphiliscaseshavebeendominatingwithapercentageof90%ofallsyphiliscases.Primarysyphiliswasthemostcommoninmalesandsecondarysyphilisinfemales.Secondaryandlatentsyphilisc