The paper aimed at identifying the impacts of factors on carbon emissions from road freight transport and predicting its future tendency. Carbon emissions from road freight transport were estimated through the method provided by Intergovernmental Panel on Climate Change (IPCC). The impacts of factors of road freight transport were summarized, and contributions of the factors were calculated based on the complete decomposition approach. A Partial Least Squares Regression model and a Multiple Linear Regression model were established to predict carbon emissions from road freight transport in China.