Environmental　vibration　induced　by　urban　elevated　road　traffic　and　railway　traffic　will　induce　secondary　vibration　of　structures.　A　theoretical　analysis　model　of　structural　secondary　vibration　was　built　and　its　equation　of　motion　is　presented.　The　generating　mechanics　of　secondary　vibration　is　discussed　in　relation　to　resonance　vibration　of　local　components　and　certain　environmental　vibrations　whose　frequency　are　close　to　that　of　the　frequency　of　the　local　components.　A　finite　element　simulation　of　the　secondary　vibration　of　a　7-story　frame　shear-wall　structure　was　carried　out　with　an　emphasis　on　the　validation　of　the　structural　secondary　vibration　theory.　It　has　been　suggested　in　the　past　that　the　whole　structure　frequency　should　be　kept　at　a　distance　from　the　site　predominant　frequency.　In　this　paper,　evidence　is　introduced　to　support　the　idea　that　the　natural　frequency　of　local　components　should　also　be　as　distant　from　the　environmental　vibration　as　possible.