Abstract: The transportation sector is the main contributor of carbon emissions in China. The article predicted the activity level of the transportation sector from 2021 to 2035 by collecting relevant information on population, economy, and transportation in each province and city from 2000 to 2020, and forecasted the activity level of the transportation sector from 2021 to 2035 by incorporating with the planning policies that have been enacted in each province and city. The emission factor method and the scenario analysis method were adopted to estimate the CO₂ emissions of different transport sectors in different scenarios for the eastern, central, and western regions, and a comparative carbon emission reduction potential was analyzed. Results show that the carbon emissions of China's transport sector under the baseline scenario exhibits a continuous growth trend, and the scenario with the greatest potential for carbon emission reduction is the scenario of adjusting the transport structure, which can reduce carbon by 721 million tonnes by 2035. Under this scenario, the road sector has a greatest potential for carbon emission reduction, the emission reduction effect from high to low is the eastern region, the western region, the central region, the aviation sector has the potential for emission reduction only in the central region, and the emission reduction potentials of the railways and the waterway sector are all negative under this scenario. The railroad, aviation and waterway sectors have greater emission reduction potential under the optimization of the energy structure scenario, which will reduce emissions by 49.30%, 20.53% and 15.66% in 2035, respectively. Under this scenario, the railway sector has superior emission reduction effects in the eastern region in the short term, and greater emission reduction potential in the central region in the long term, while the aviation sector's emission reduction potentials are better in the east and west, and the emission reduction effect of the waterway sector is more significant in the eastern region.