The　spatial　and　temporal　characteristics　of　residents＇　medical　treatment　reflect　the　service　capacity　and　layout　rationality　of　medical　facilities.　This　study　investigated　the　features　and　patterns　of　medical　treatment　using　taxi　trajectory　data　in　Xiamen.　We　divided　Xiamen　Island　into　different　research　units　based　upon　the　central　lines　of　roads.　We　presented　a　trajectory　drift　algorithm　to　extract　the　medical　treatment　OD　data　for　tertiary　hospitals.　This　algorithm　deals　with　the　positional　error　associated　with　trajectory　data　and　can　improve　the　extraction　accuracy.　Hospitalizing　behavior　was　analyzed　from　the　perspective　of　space　and　time.　Finally,　based　on　the　residents＇　preference　for　hospitals,　we　discussed　the　spatial　patterns　of　residents＇　medical　treatment　by　K-means　algorithm.　The　results　show　that:　(1)　Compared　with　traditional　buffer　analysis,　the　trajectory　drift　algorithm　didn＇t　require　high　positioning　accuracy　when　extracting　OD　data　for　hospitals.　OD　data　can　be　extracted　more　reasonably　and　completely　only　by　shifting　OD　point＇s　coordinates,　with　an　accuracy　increased　by　more　than　30%.　It　was　also　applicable　to　all　floating　vehicle　trajectory　data;　(2)　The　peak　time　of　medical　treatment　occurred　at　7　am　and　2　pm,　respectively.　The　number　of　medical　visits　was　twice　on　weekends　(including　holidays)　than　working　days.　When　the　travel　distance　was　greater　than　1　km,　the　number　of　medical　visits　decreased　with　the　increase　of　travel　distance,　following　a　Weibull　function　distribution;　(3)　Residents　regarded　the　Zhongshan,　the　First　Affiliated,　and　the　Chinese　Medicine　Hospital　as　their　first　choice　for　medical　treatment.　There　was　a　significant　regional　difference　in　choices　of　medical　treatment,　that　is　residents　preferred　nearby　hospitals.　The　southwest　of　Xiamen　Island　had　sufficient　medical　resources,　and　residents＇　average　medical　travel　distance　was　less　than　4　km.　However,　residents　in　northwest　and　southeast　of　Xiamen　Island　mostly　had　to　travel　about　10　km　for　medical　treatment.　The　medical　resources　in　these　regions　were　relatively　scarce　and　needed　to　be　strengthened　eagerly;　(4)　The　service　capacity　of　the　nine　tertiary　hospitals　in　Xiamen　Island　was　obviously　different.　The　residents　had　a　strong　preference　for　the　Zhongshan,　the　First　Affiliated,　and　the　Chinese　Medicine　hospitals,　with　evaluated　preference　values　greater　than　33%.　The　service　scopes　of　these　three　hospitals　basically　covered　the　whole　Xiamen　Island,　which　indicated　strong　attraction　and　service　capacity　for　the　residents.　The　values　of　residents＇　preference　for　the　other　six　hospitals　ranged　from　0　to　33%.　These　six　hospitals　mainly　treated　nearby　residents,　leading　to　weak　attraction　and　service　capacity.　This　study　provides　alternative　methods　to　extract　the　spatiotemporal　features　of　residents＇　medical　treatment　and　supports　the　decision-making　of　optimizing　the　spatial　configuration　of　medical　facilities.　©　2021,　Science　Press.　All　right　reserved.