A　multi-span　bridge　with　hollow-slabs　was　retrofitted　into　a　jointless　bridge,　in　which　the　simple　support　slabs　were　converted　into　the　continuous　slabs　with　double　row　supports　and　the　general　abutments　were　converted　into　deck-extension　abutments,　thus,　all　movable　deck　joints　of　the　bridge　were　eliminated.　The　static　and　dynamic　load　tests　of　jointless　retrofitted　bridge　with　multi-span　hollow-slabs　were　carried　out,　and　the　mechanical　performance　of　the　bridge　was　studied.　The　finite　element　model　was　used　to　calculate　the　structural　mechanical　performance,　bearing　capacity　and　mechanical　performance　of　approach　slab,　and　to　analyze　the　influence　of　single　and　double　rows　supports　on　the　structural　mechanical　performance.　Test　result　shows　that　after　jointless　retrofitting,　the　tested　fundamental　frequency　of　the　bridge　is　8.60　Hz　and　larger　than　5.37　Hz　before　jointless　retrofitting.　The　maximum　tested　impact　factor　is　1.11　of　four　vehicle　speeds　and　smaller　than　1.36　that　is　the　calculated　value　by　the　General　Specifications　for　Design　of　Highway　Bridges　and　Culverts(JTG　D60-2004).　The　verification　coefficients　of　the　strain　and　deflection　are　less　than　0.95.　Obviously,　the　jointless　retrofitting　enhances　the　integrality　of　the　bridge　and　improves　the　driving　comfortability.　The　finite　element　analysis　result　shows　that　after　jointless　retrofitting,　the　fundamental　frequency　of　the　bridge　is　8.48　Hz,　and　the　ratio　is　1.01　between　the　tested　fundamental　frequency　and　calculated　result,　so　the　bridge　is　in　good　working　condition.　The　positive　bending　moments　of　mid-span　sections　reduce　significantly　with　a　maximum　value　of　15.6%　at　the　second　span,　while　the　negative　bending　moments　appear　at　the　inner-supports　and　the　shear　forces　near　the　inner-supports　increase　with　a　maximum　value　of　18.2%.　The　mid-span　deflections　decrease　obviously　with　a　maximum　value　of　35.5%　at　the　second　and　third　spans,　which　indicates　that　the　integral　stiffness　of　the　bridge　improves　significantly.　The　calculated　maximum　crack　width　is　0.15　mm　and　smaller　than　0.20　mm　that　is　the　allowable　value　in　the　Code　for　Design　of　Highway　Reinforced　Concrete　and　Prestressed　Concrete　Bridges　and　Culverts(JTG　D62-2004)(Bridge　Code　for　short),　and　the　checking　results　of　bearing　capacity,　deflection　and　crack　width　meet　the　requirement　of　Bridge　Code.　The　rows　of　supports　have　no　significant　effect　on　the　inner　forces　of　the　superstructure,　and　the　double　row　supports　are　feasible.　The　friction　coefficient　between　the　approach　slab　and　its　subgrade　has　significant　influence　on　the　axial　forces　of　the　approach　slabs　and　the　pavement,　but　has　no　significant　effect　on　the　bending　moment.　The　maximum　tensile　stresses　of　the　approach　slab　and　pavement　are　0.87　and　1.25　MPa,　respectively,　which　meets　the　strength　design　requirement.　11　tabs,　17　figs,　30　refs.　©　2018,　Editorial　Department　of　Journal　of　Traffic　and　Transportation　Engineering.　All　right　reserved.