This paper adopts the legitimacy theory and stakeholder theory perspectives to explore the drivers of voluntary carbon disclosure among Chinese firms under the 11th and 12th Five-Year Plans. We use the coding technique of content analysis to capture quantitative data of carbon reduction and classify sample firms by disclosure content into three groups and then apply ordinal logit regression to test the proposed hypotheses. Firm size (Size) and profitability (Profit) are positively related to carbon disclosure; SOE blockholder (State-bloc) and high carbon emission industries (HCEI) are significantly more dedicated to carbon disclosure. However, POE blockholder (Private-bloc) and creditors (Lev) are negatively related to carbon disclosure. We also find that the effects of HCEI and Ownership differ most widely between firms in coastal areas and firms in non-coastal areas; State-bloc is more significantly related to carbon disclosure in the 12th-five period than in the 11th-five period. Chinese firms should understand that taking substantive actions of carbon disclosure, fulfilling social responsibilities, and aligning their operations to the planned economy can contribute to their sustainable development. This paper offers evidence of variations in drivers of carbon disclosure, and such variations are attributable to the differences between the two plan periods and between geographical regions. The evidence is helpful for understanding what have motivated Chinese firms to disclose carbon emission information in the two different plan periods and in different geographical areas.