Issues raised in this paper are: First, how do we know whether the strike conducted by the employers is a legal one? Second, how do we protect employers from some invalid strike actions? This research is a normative juridical (legal normative research). The approach used in this study is legislative approach (statute approach) and the conceptual approach. The study concluded, first, that employersâ€™ strikes will belong to legal ones if: a) a deliberation about the specifics of disputes between the unions and employers has been truly held; b) the request of negotiation has been truly rejected by the owners; c) they has been failed in two times within a period of two (2) weeks to invite other parties to negotiate. Second, the employer could do either the refusal to the implementation of a strike in the framework of the three stages; before, during and after the strike; or did lock out done by the owners.