Credit market, as a main component of financial market, plays a significant role in building up the savings and providing financial facilities for the firms. Better knowledge of the influential factors in the development of this market, not only enhances the analytical capability of researchers but also acts as a suitable guide for policy-makers. This study, having used the depth of credit information index and strength of legal right index, as provided by the World Bank, and the data of 42 developing countries during (2005-2008), makes an empirical study to determine whether increase in legal support of creditors in bankruptcy, collateral law and borrowers rights in collateral law, as well as the quality of the shared credit information and vastness of their gathering domain, have a meaningful effect on credit market development or not. This econometric model doesn't reject this hypothesis, that is, the countries that provide higher legal support for creditors in bankruptcy and in collateral law and provide further protection of borrowers' rights in collateral rights have better developed credit markets. Moreover, the credit market in countries where the shared credit information is collected from vaster sources and enjoy higher quality, are more developed. Regarding the numerous problems of the state firms in having access to credit, carrying out reforms to enhance the strength of legal rights index and the depth of credit information index not only improves the status of Iran in these indexes but also may be a positive step toward the development of credit market.