This paper considers the event-triggered leader-follower tracking control for interconnected systems. Unlike the large body of existing work, here we consider systems which are physically coupled with uncertain norm-bounded coupling between the subsystems. We propose a model based event-triggered tracking control strategy and an event triggering rule with a time-dependent threshold which guarantees that the tracking errors in the systems asymptotically converge to zero. With the proposed event triggering rule, we prove that the systems do not exhibit Zeno behavior. In addition, the proposed event-triggered tracking control strategy is also employed to decoupled multi-agent systems. The efficacy of the proposed method is discussed using a simulation example.