Multiple-color-emissive　carbon　dots　(CDots)　have　potential　applications　in　various　fields　such　as　bioimaging,　light-emitting　devices,　and　photocatalysis.　The　majority　of　the　current　CDots　to　date　exhibit　excitation-wavelength-dependent　emissions　with　their　maximum　emission　limited　at　the　blue-light　region.　Here,　a　synthesis　of　multiple-color-emission　CDots　by　controlled　graphitization　and　surface　function　is　reported.　The　CDots　are　synthesized　through　controlled　thermal　pyrolysis　of　citric　acid　and　urea.　By　regulating　the　thermal-pyrolysis　temperature　and　ratio　of　reactants,　the　maximum　emission　of　the　resulting　CDots　gradually　shifts　from　blue　to　red　light,　covering　the　entire　light　spectrum.　Specifically,　the　emission　position　of　the　CDots　can　be　tuned　from　430　to　630　nm　through　controlling　the　extent　of　graphitization　and　the　amount　of　surface　functional　groups,　COOH.　The　relative　photoluminescence　quantum　yields　of　the　CDots　with　blue,　green,　and　red　emission　reach　up　to　52.6%,　35.1%,　and　12.9%,　respectively.　Furthermore,　it　is　demonstrated　that　the　CDots　can　be　uniformly　dispersed　into　epoxy　resins　and　be　fabricated　as　transparent　CDots/epoxy　composites　for　multiple-color-　and　white-light-emitting　devices.　This　research　opens　a　door　for　developing　low-cost　CDots　as　alternative　phosphors　for　light-emitting　devices.