Abstract: To assess the application potential of emission reduction technologies for ships calling at Shanghai Port,this study develops a bottom-up at-berth emissions inventory for auxiliary engines and boilers based on AIS data and vessel characteristics. Four scenarios are evaluated: 0.1% ULSFO,LNG fuel,shore power for non-tanker vessels,and shore power for all vessel types. The results show that LNG provides the most comprehensive pollutant reductions. Shore power for all vessel types reduces in-port non-carbon pollutants by over 80%,but its carbon mitigation effect is constrained by operational efficiency and the grid carbon intensity. By contrast,0.1% ULSFO mainly reduces SO_x and PM2. 5. The cost-benefit analysis indicates that NO_x reduction contributes the largest share of social benefits. Under current market conditions,subsidies are the key determinant of technological economic viability. Only shore power for all vessel types approaches break-even when large-industrial electricity tariffs are available and operational and grid-related conditions are satisfied,whereas 0.1% ULSFO has the weakest economic performance due to its high cost and limited benefits. The findings can provide a basis for differentiated emission reduction decision-making in ports.