Abstract: By building mathematical models, This paper studies the influence of abatement R&D subsidy to emissions reductions, emissions trading market, the enterprise profit and social welfare under the condition of emissions trading, and further analyzes the relevant supporting policies. The result shows that: abatement R&D subsidy can adjust the emission trading market effectively. Under the condition of emissions trading, abatement R&D subsidy has a good emission reduction effect, and can improve the level of corporate profit and social welfare. Finally, we find that pollution tax is the optimal policy for abatement R&D subsidy, choose the appropriate pollution tax will improve the level of emission reduction, firm profit and social welfare , which can realize the sustainable development of economy.