In thispaperanoptimalsecondorderslidingmodecontroller(OSOSMC)isproposedtotrackalinear uncertain system.Theoptimalcontrollerbasedonthelinearquadraticregulatormethodisdesignedfor the nominalsystem.Anintegralslidingmodecontrolleriscombinedwiththeoptimalcontrollerto ensure robustnessofthelinearsystemwhichisaffectedbyparametricuncertaintiesandexternal disturbances. Toachieve finite timeconvergenceoftheslidingmode,anonsingularterminalsliding surface isaddedwiththeintegralslidingsurfacegivingrisetoasecondorderslidingmodecontroller. The mainadvantageoftheproposedOSOSMCisthatthecontrolinputissubstantiallyreducedandit becomes chatteringfree.