The port planning Environmental Impact Assessment (EIA) aims to evaluate the main environmental impacts at the early stage of a project and integrate prevention and mitigation measures into the decision-making of project development. The report intends to introduce international experiences of mobile source emissions assessments in ports, especially the cases from the Port of Rotterdam in the Netherlands and the Port of Los Angeles and the Port of Long Beach in the U.S., and thereby to support China to improve its implementation of the mobile source emission assessment in the Port EIA.