Discrete　Fourier　transform　has　many　advantages,　such　as　easy　for　embedding,　high　efficiency,　and　etc,　so　it　is　widely　used　in　synchronized　phasor　measurement　in　power　system.　However,　due　to　the　existence　of　non-synchronous　sampling　and　frequency　domain　discretization,　the　spectrum　leakage　and　fence　which　cause　the　errors　of　calculation　result　will　occur　when　the　DFT　is　used　in　phase　measurement.　To　solve　this　problem,　in　this　paper　the　equations　of　phase　angle　error　are　deduced　in　the　non-synchronous　sampling,　then　the　difference　of　phase　angles　is　utilized　to　track　the　frequency　of　power　measurement　signal.　Accordingly　a　method　of　synchronized　phasor　measurement　based　on　improved　DFT　algorithm　is　proposed.　The　calculation　results　of　improved　DFT　algorithm　are　divided　into　an　integer　part　and　a　fractional　part,　and　the　fractional　part　is　modified　by　the　equivalent　replacement.　The　simulation　results　show　that　the　method　has　higher　accuracy　and　anti-jamming　capability,　and　the　performance　has　greatly　improvement　compared　with　the　traditional　algorithm.　On　this　basis,　a　phasor　measurements　unit　hardware　system　is　designed　by　using　TMS320F2812.　Utilizing　it,　accurate　measurement　results　of　frequency,　amplitude　and　phase　angle　are　obtained.　©　2017,　The　editorial　office　of　Transaction　of　China　Electrotechnical　Society.　All　right　reserved.