The implementation of National Emission Trading Scheme(National ETS) in China aims to constrain excessive carbon emissions and promote energy conservation. However, it has been a controversial issue which part of electricity market participants should undertake the cost for excessive emission. Power generators are the direct emitters while electricity customers are the underlying drivers of carbon emissions. Different restriction objects in ETS may influence its emission mitigation effect. Therefore, this paper compares the policy impacts of bilateral pricing with unilateral pricing by implementing empirical experiments with the real market data and policy parameters in Guangdong province. The paper proposes carbon-oriented demand response (CDR), takes the arbitrage profit between the electricity market and emission trading markets as one motivator of customers participating DR. Based on different cases simulation, the overall emission mitigation effect and the changes in user behavior in the power market when introducing different sides into carbon market are compared.The paper discovers that under the current electricity market mechanism in China, the power generation pricing cannot fully transfer the carbon emission cost to the customers. Involving the participation of both demand-side and supply-side is more suitable for China to minimize the overall emission.