DescriptionSliding mode control is a form of variable structure control which is a powerful tool to cope with external disturbances and uncertainty. There are many applications of sliding mode control of weakly coupled system to absorption columns, catalytic crackers, chemical plants, chemical reactors, helicopters, satellites, flexible beams, cold-rolling mills, power systems, electrical circuits, computer/communication networks, etc. In this thesis, the problem of sliding mode control for systems, which are composed of two weakly coupled subsystems, is firstly addressed. This thesis presents three methods to study continuous-time linear weakly coupled systems using sliding mode control. First one is Utkin and Young's sliding mode control method for each subsystem using a decoupling transformation technique. Next one is a composite control approach composed of two controllers, which are a state feedback controller and a sliding mode controller. The last one is a sliding mode control technique using the Lyapunov approach. These methods provide controls which make the systems asymptotic stabile with a robust performance against parametric uncertainties and exogenous disturbances. In this thesis, we demonstrate the effectiveness of the proposed methods through theoretical and simulation results.