This study aims to analyze the carbon dioxide emission characteristics of ships berthed at major ports in Korea by identifying emission levels by port and ship type, providing foundational data necessary for the formulation of future emission reduction policies. Using Port-MIS data, the study collects and analyzes data on berthed ships from the past five years, from 2019 to 2023. The results reveal that tankers and cargo vessels account for the majority of total emissions, with higher emissions observed at major commercial ports such as Busan, Ulsan, and Gwangyang. Notably, tankers exhibited higher emissions than other types due to increased generator usage during berthing, driven by cargo heating and steam-driven pumps. These findings underscore the need to expand Alternative Maritime Power (AMP) installations at ports, with a particular focus on berths that accommodate tankers. This study is expected to contribute to the systematic understanding of carbon dioxide emissions from berthed ships at domestic ports, aiding in the formulation of efficient emission reduction strategies.