Abstract : French listed companies are developing disclosure strategies about intellectual capital for many years. The central question to the dissertation is based on this observation : what motivates companies to communicate on intellectual capital components which exceed or complete accounting disclosure. The first part reminds the developement of intellectual capital in the companies management and in economics. Cases study introduces a intellectual conceptual definition. The second part offers cluster and factor analysis of voluntary and accounting intellectual capital disclosure, about SBF 120 french listed. Multivariate tests show that some limitations to use agency and political theory for this study. But, the researche conclude that sector, intangible contribution in the balance sheet and the auditor type appear to influence the intellectual capital disclosure in a significant manner.