The research showed, in aggregate, a trend of increasing amounts of corporate social disclosure, although the five-year trends varied within different industries. CSR among Thai companies was found to be primarily focused on human resources, providing “declarative” good news disclosures. Legitimacy theory, political economy theory and economic conditions were used to present explanations for the trends. The study concluded that while no single perspective can explain the disclosure of CSR, the empirical findings demonstrate that the key areas of company social exposure are reflected by CSR.