The true behavior of the connections is usually semi-rigid. Neglecting the real behavior of the connection in the analysis may lead to unrealistic predictions of the response and reliability of steel frames. In this paper the methodology for determination of rotational stiffness of semi-rigid connection in steel constructions according to Eurocode 3 componential method has been analyzed. By application of this concept the determination of rotational connection response comes down to determination of geometrical characteristic of different connection components. This paper considers the effects of semi-rigid behavior of the connections in analysis for steel frames and ways for global optimization of structural members and optimization of joint especially. In this paper, steel frames are
analyzed by using computer program. Having the same geometry and cross-section, the static analysis for frames is examined for three different type of connections. The first frame is analyzed with ideally rigid connection, second one with semi-rigid connection and third one with ideally pinned connection.