Consensus tracking control problems for single-integrator dynamics of multi-agent systems with switching topology are investigated.In order to design effective consensus tracking protocols for a more general class of networks,which are aimed at ensuring that the concerned states of agents converge to a constant or time-varying reference state,new consensus tracking protocols with a constant and time-varying reference state are proposed,respectively.Particularly,by contrast with spanning tree,an improved condition of switching interaction topology is presented.And then,convergence analysis of two consensus tracking protocols is provided by Lyapunov stability theory.Moreover,consensus tracking protocol with a time-varying reference state is extended to achieve the formation control.By introducing formation structure set,each agent can gain its individual desired trajectory.Finally,several simulations are worked out to illustrate the effectiveness of theoretical results.The test results show that the states of agents can converge to a desired constant or time-varying reference state.In addition,by selecting appropriate structure set,agents can maintain the expected formation under random switching interaction topologies.