Assessing marginal abatement costs (MAC) of emissions improve the understanding of the extent of current CO2 mitigation and provide regions and industries with information on how to mitigate emissions cost-effectively. This study proposes a hybrid method to evaluate MAC, which combines the strengths of bottom-up engineering methods and top-down economy-wide methods. A parametric directional distance function is employed to estimate MAC from an economic perspective, and the abatement level is further incorporated to generate increasing curves, which is similar to the outcomes derived from an engineering perspective. In addition, this method takes into consideration whether the abatement level exceeds the abatement potential with current production technologies so as to provide a more realistic estimation of the MAC curve. The proposed technique is applied in estimating the carbon emission MAC in China's petroleum industry. The estimation results indicate that: i) the MAC of China's petroleum industry would change from 9,821 Yuan/ton to 16,307 Yuan/ton when the abatement level increases from 1% to 50%; ii) this industry would spend 36.5 to 42.5 billion Chinese Yuan annually to achieve China's CO2 reduction target proposed in the Intended Nationally Determined Contributions (NDCs); iii) assigning the CO2 reduction targets based on the estimated MAC curves instead of the traditional grandfathering abatement target assignment would help to save additional 29.97% to 33.65% abatement cost for China's petroleum industry for achieving the NDCs.The MAC curves estimated in this study indicate more accurate relationships between abatement levels and abatement costs which provides the decision-makers both in industries and governments with a more reliable instrument to determine prices of emission permits, total abatement costs, and implementation strategies in an emission trading scheme.