Broken　rotor　bars　change　the　inherent　symmetry　of　motor　winding　and　bring　the　difficulty　of　modeling　and　simulation.　The　easy-solved　mathematical　model　of　the　broken-rotor-bars　squirrel-cage　induction　motor　is　established　with　synthetic　vector　for　the　question.　Simulation　on　both　the　transient　and　the　steady　states　of　the　motor　reveals　the　fault　features　that　both　the　amplitude　of　stator　current　and　the　electromagnetic　torque　are　pulsed　varying　with　time.　The　rotor　bar　current　distribution　is　obtained,　which　shows　that　current　has　the　highest　value　in　the　bars　next　to　the　broken　one　and　away　from　one　pair-pole＇s　space.　It　is　noteworthy　that　the　voltage,　which　indicates　the　degree　of　asymmetry　of　rotor　circuit,　appears　between　two　end-rings　of　the　rotor.　Meanwhile,　the　paper　illustrates　how　the　fault　features　change　with　the　motor　load.　The　simulation　results　are　helpful　for　the　on-line　diagnosis,　troubleshooting　on　the　induction　motor.　The　measured　stator　current　is　in　accord　with　simulation　result,　thus　confirming　the　conclusion＇s　correctness.