Urban　development　status　is　closely　related　to　the　urban　economy,　environment,　ecology,　and　health.　Spatial　and　socioeconomic　processes　are　the　two　key　aspects　of　urban　development,　so　the　absence　of　any　of　them　will　affect　the　assessment　of　urban　development　status.　In　this　study,　using　both　spatial　and　socioeconomic　information　from　land　cover　data　and　nighttime　light　data,　respectively,　we　proposed　an　exponential　model,　Spatial-Socioeconomic　Urban　Development　Curve　(SSUDC),　to　provide　a　quantitative　expression　of　the　relationship　between　the　two　key　processes　of　urban　development　and　analyze　urban　development　status.　The　SSUDC　was　calculated　from　the　artificial　surface　ratio　at　1%　intervals　obtained　from　Globeland30　land　cover　data　and　the　corresponding　average　NPP-VIIRS　nighttime　light　radiance　data,　using　a　nonlinear　least-squares　method.　We　generated　SSUDCs　for　330　prefecture-level　cities　in　Mainland　China,　208　of　which　had　coefficients　of　determination　(R2)　greater　than　0.6.　Taking　Ordos　and　Guiyang　as　two　typical　examples,　we　analyzed　the　importance　and　advantages　of　SSUDC.　The　coefficients　α　and　β　of　the　exponential　SSUDC　were　shown　to　indicate　the　base　intensity　socioeconomic　activity　and　the　concentration　of　socioeconomic　activities,　respectively,　and　can　be　used　to　reveal　the　urban　socioeconomic　development　status　and　functional　type　of　cities.　At　the　internal　urban　level,　the　residuals　of　SSUDC　can　imply　the　demand　for　urban　physical　or　economic　construction　in　different　areas　of　the　city,　and　even　the　urban　growth　type,　together　with　the　distribution　of　the　artificial　surface　ratio.　In　summary,　the　proposed　SSUDC　provides　a　simple　way　to　combine　the　spatial　and　socioeconomic　processes　of　urban　development,　which　is　beneficial　to　the　analysis　of　urban　development　at　different　scales　and　a　rewarding　tool　for　urban　planning.　©　2019　by　the　authors.