The gap of energy-related-CO_2 emission pathways between the Nationally Determined Contributions (NDCs) submitted to United Nations Framework Convention on Climate Change (UNFCCC) and realizing the target of limiting temperature rise below 2℃ was researched based on an integrated assessment modal of climate changeGlobal Change Assessment Model (GCAM-TU). Results show that the NDCs are not enough to realize the target. Each country or party should enhance its NDC after 2030. The analyses of carbon intensity reduction, abatement costs, and carbon emission per capita of the main countries and parties demonstrate the great efforts and contributions of China in the process of global emission reduction. On the contrary, the commitments of regions like South Africa and Japan seem insufficient. To meet the commitment, the final energy consumption of China would reduce compared with the reference scenario, and the energy structure would have a further optimization.