'Green card' is the common Chinese term for the U.S. permanent resident card — an official document proving legal permanent residency in the United States. Though the card has changed color over time (and is no longer always green), the name 绿卡 has stuck due to its historical association with the original green-colored version issued in the 1950s. The character 绿 means 'green', and 卡 is a loanword meaning 'card', borrowed from English and used widely in modern Chinese for various identification or access cards.

This term is used almost exclusively in contexts related to U.S. immigration, visa processes, or discussions about living and working long-term in America. It carries strong connotations of opportunity, stability, and legal status — but also reflects the challenges of obtaining it. Unlike general terms like 居留证 (residence permit), 绿卡 specifically refers to the U.S. system and is rarely used metaphorically for other countries’ residency documents.