In　this　paper,　a　sampled-data　controller　is　designed　for　the　exact　discrete-time　model　of　nonholonomic　mobile　robots,　which　solves　the　leader-following　consensus　problem.　We　describe　the　uniform　global　asymptotic　stability　of　closed-loop　systems　with　time-varying　and　periodic　characteristics　through　the　generalized　Krasovskii-LaSalle　Theorem　together　with　the　stability　theorem　of　cascaded　system.　A　numerical　simulation　is　used　to　illustrate　our　conclusions.