Cities　that　experience　earthquake　disasters　face　a　lot　of　uncertainties　and　unsustainability　resulting　from　the　fragility　of　their　infrastructure,　which　should　be　considered　in　engineering.　This　study　proposes　a　seismic　fragility　assessment　framework　for　urban　functional　spatial　units　in　order　to　improve　the　traditional　structural　fragility　assessment　criteria　that　are　currently　applied　in　urban　planning.　First,　appropriate　spatial　units　are　classified　for　the　study　area,　the　functional　categories　of　the　study　area　are　determined　using　urban　Point　of　Interest　(POI)　data,　and　the　functional　proportion　of　the　spatial　units　is　calculated.　Secondly,　considering　the　classification　of　different　seismic　fortification　levels　represented　by　different　construction　ages,　and　considering　the　possible　building　forms　and　HAZUS＇s　classification　system　of　building　structures　in　order　to　establish　the　correlation　between　building　functions　and　building　structures,　the　methods　of　a　field　survey　and　a　questionnaire　survey　are　adopted　to　match　the　functions　with　the　most　likely　building　structures.　After　this,　based　on　the　assumption　of　the　lognormal　distribution　of　ground　motion　intensity,　a　mixed　method　is　adopted　to　calculate　the　mean　value　mu(SIC)　for　the　fragility　of　functional　space　units.　The　Monte　Carlo　method　is　then　used　to　discretize　the　data　and　statistically　obtain　the　standard　deviation　beta(SIC)　for　the　fragility　of　functional　space　units,　and　the　fragility　curve　is　then　fitted.　A　district　in　Xuzhou　City,　China,　was　used　as　a　case　study　to　verify　this　assessment　framework.　The　results　showed　that:　(1)　the　fragility　of　functional　space　units　was　greatly　affected　by　the　proportion　of　defense　standards　in　different　periods　in　the　unit,　which　reflected　the　average　level　of　fragility　within　the　unit.　(2)　The　unit　loss　index　of　units　built　after　2001　with　a　proportion　of　less　than　50%　is　basically　above　the　average　loss　level　of　the　study　area.　(3)　The　simulated　damage　ratio　of　the　assessment　results　under　the　three　levels,　namely　frequent　earthquake,　fortified　earthquake　and　rare　earthquake,　is　consistent　with　the　previously　experienced　earthquake　damage.　The　paper　concludes　that　it　is　helpful　to　design　and　utilize　seismic　fragility　predicting　formulas　and　technologies　at　the　functional　spatial　unit　level　for　urban　planning,　which　is　meaningful　for　the　formulation　of　planning　strategies,　reducing　risks　to　infrastructure　and　delivering　sustainable　development.