This　paper　presents　the　modelling　and　experimental　evaluation　of　a　semi-active　vehicle　suspension　installed　with　a　self-powered　MR　damper　which　is　able　to　perform　variable　stiffness.　Its　variable　stiffness　feature　as　well　as　the　self-powering　capability　was　evaluated　and　verified　using　a　hydraulic　Instron　test　system.　The　testing　results　show　that　the　stiffness　of　the　damper　is　dependent　on　the　current　which　can　be　generated　by　the　self-powering　component.　A　mathematic　model　was　established　to　describe　the　dynamic　properties　of　the　MR　damper　and　its　power-generating　capability.　Finally,　the　self-powered　MR　suspension　was　installed　on　a　quarter　car　test　rig　for　its　vibration　isolation　evaluation.　A　controller　based　on　the　short-time　Fourier　transform　(STFT)　was　developed　for　the　stiffness　control.　The　evaluation　result　illustrates　that　the　proposed　MR　damper　can　reduce　the　acceleration　and　displacement　of　the　sprung　mass　by　16.8%　and　21.4%　respectively,　compared　with　the　passive　system.