Choi's native language is Korean. Choi writes about her own experiences as a young refugee from North Korea during the Korean War through her heroines in her books. She said, "I now have two countries, my native country of Korea, and my adopted country, the United States. Through my writing, I want to bring to life the history and culture of Korea to share with all my American friends."
In her first young adult book, The Year of Impossible Goodbyes (1991), Choi writes about 10-year-old Sookan's life and her family during the brutal Japanese occupation of the Korean Peninsula. When World War II ends, the Russian Army occupies the area north of the 38th Parallel thus creating Communist North Korea. This is the story of Sookan's life under the Japanese and Russian Occupation, and her harrowing escape from North Korea to South Korea in search of freedom.
The book won numerous awards including Best Books for Young Adults, ALA Notable Book and Judy Lopez Book Award by the National Women's Book Association. It has been translated into several languages including Korean, French, Italian, and Japanese. It is also available in Braille and in audio book.
Her books can be used not only to promote reading and writing, but also to tie literature into the social studies curriculum in middle schools, high schools, and also political science at the college level. Choi's books explore themes of communism, freedom, international politics, and interaction among nations. They can be used to teach about socio-geopolitical events and historical realities of Asian nations, including how big powers affect the fate of small nations.