Abstract An essential issue in future climate negotiations is how to bring developing countries on board. This paper proposes and applies the two-level interest-based model to analyze the factors that affect the likely stances of the “Plus Five” countries (Brazil, China, India, Mexico, and South Africa) on international climate negotiations. This study finds mitigation capability to be a crucial factor which consists of at least such sub-factors as per capita income, energy endowment, and economic structure, while ecological vulnerability does not seem to play an important role which includes reductions in agricultural outputs, sea-level rise, climate-related natural disasters, and others. The paper proposes six options in an ascending order of stringency that the Plus Five are likely to adopt. The paper suggests that the “Basic Four” (the Plus Five excluding Mexico), particularly China and India, are less likely to adopt a voluntary commitment to an emissions cap on the national economy in the near future than Mexico, which has the highest mitigation capability among all five. The Basic Four are likely to adopt more stringent climate polices with increasing mitigation capabilities, suggesting the importance of effective international financial and technology transfer mechanisms and further tighten emission reduction targets from developed countries.