In this paper an adaptive sliding mode controller is presented for a class of master-slave chaotic
synchronization \u00a0systems \u00a0with \u00a0uncertainties. \u00a0The \u00a0concept \u00a0of \u00a0extended \u00a0systems \u00a0is \u00a0used \u00a0such \u00a0that \u00a0continuous
control input is obtained using a sliding mode design scheme. By comparing with the results in the existed
literatures, \u00a0the \u00a0results \u00a0show \u00a0that \u00a0the \u00a0master-slave \u00a0chaotic \u00a0systems \u00a0with \u00a0uncertainties \u00a0can \u00a0be \u00a0synchronized
accurately by this controller. Illustrative examples of chaos synchronization for uncertain Willis system are
presented to demonstrate the superiority of the obtained results.
