This paper gives a review for optimal control problems with state variablerninequality constraints. To solve the problem with pure state inequality constraint,rnwe use different approaches such that: direct adjoint approach, thernindirect adjoining approach with complementary slackness (first order constraints),rnthe indirect adjoining approach for higher order constraints and thernindirect adjoining approach with continuous adjoint functions. Furthermore,rnthe application of optimal control problems conditions is demonstrated byrnsolving illustrative examples.rnKeywords: Optimal control problems, pure state inequality constraint andrnmixed state inequality constraint