A collective agreement is an agreement regulating conditions to be observed in employment contracts or otherwise in employment relations, concluded by a single employer or employers` association on one side, and trade union on the other side. Art. 33(Validity of Terms and Conditions) of Trade Union and Labor Relations Adjustment Act (TULRAA): “Part of the rules of employment or contract of employment which violates the standards concerning working conditions and other treatment of workers specified in collective agreement shall be null and void(§33 ①)”, and “Matters which are not stipulated by a contract of employment, and what has been invalidated by paragraph (1), shall be governed by the terms and conditions of collective agreement(§33 ②).” With respect to the legal status of the collective agreement, the status of the collective agreement is considered to be contractual, but the normative effect of collectively agreed terms in relation to third parties has required statutory basis, set out in the TULRAA. TULRAA §33 provides only operational method of normative effect, does not clarify legal grounds of normative effect. This article regard TULRAA §33 which is formative law of basic right as the result of exercising labor fundamental rights and as ordering effect in collective agreement which is the result of the freedom to conclude agreement. The normative effect of the collective agreement is not established to improve work conditions by a national policy but has the Constitutional legitimacy. In other words, the Art. 33 of the Constitution (labor fundamental rights: right to organize, right to bargain collectively, right to strike) guarantees trade unions and employers associations the freedom to conclude agreements (Tarifautonomie). The normative effect of the collective agreement is included in the freedom to conclude agreements and the Constitutional will made by the Framers of the Constitution is concretized in Art. 33 of TULRAA.