Considering the growing enlargement trend of ships in the upper Yangtze River，it is of great significance for waterway construction planning to assess the impact of this trend on typical pollution emissions.Therefore，we collect and calculate the data on the tonnage，traffic flow，fuel consumption，and typical pollutant emissions of ships in the upper Yangtze River and analyze the comprehensive impact of ship enlargement on typical pollutant emissions.The results are shown as follows：1）The average tonnage of ships in three provinces and one city of the upper Yangtze River increased from 249 to 874 tons from 2008 to 2019，with a significant decrease in the traffic flow and a significant increase in the freight volume.2）The waterway class of the upper Yangtze River has upgraded from Class Ⅳ to Class Ⅲ，and the typical air pollution emissions per unit turnover of ships in ideal conditions have been reduced by 31.2%.3）The increase in waterway freight turnover leads to the growth in total pollution emissions from ships，but the calculations on the average tonnage of enlarged ships show that the waterway transport from 2008 to 2019，a replacement for land transport，lessens the pollution emissions by about 1.9 million tons，which registers a growth rate of 7.7% in pollution emission reduction compared to that on the average tonnage of ships in a constant state.4）It is proposed to upgrade the waterway class of the upper Yangtze River to Class II and further promote the development of ship enlargement.In this way，the typical air pollution emissions per unit turnover of ships can be reduced by 36.4% relative to the Class III waterway，which can facilitate the transport industry to achieve the goal of “carbon neutrality.”