Investors, financial analysts, and government authorities rely on information disclosed by companies to make their investment decisions, analyze and recommend shares, or to promulgate regulations. The complexity of current business world and the globalization of economies have however raised difficulties for information users in understanding different disclosure practices across countries and across corporates. This thesis advances the literature on corporate disclosure by illustrating comprehensively the disclosure determinants originating at firm systems and country systems. the results indicate that firm-level disclosure determinants are hierarchically correlated with those reflect national environment. Once this clustering effect is adjusted, only national legal systems and economic growth are the most significant country-level disclosure determinants. Methodologically, this study eventually applies the multilevel latent variable approach that can overcome some main limits inherent to the traditional single-level regression test.