semantics of "Misaq Qaliz" and discussing its basic factors, and faithfulness in The present research aims to discuss about Quranic phrase "Misaq Qhaliz", according to Quran›s verses and semantic analysis and commentators reviews, to clear the holy place of marriage and necessity of faithfulness to it. Then we discussed two main factors to outbreak this faithfulness, namely, Faith, which belong to soul, the inner part of human, and "Moa›sherat be ma›rouf", convenient communication, which is related to behavior and Morality, to show guidelines to accomplishment the tenth principle of constitution. This article, in the end, suggested that «faithfulness to marriage» shall be mention in the law and the word «misaq» referring to marriage, must be emphasised in didactic texts, media and colloquies.