Her research interests include number theory and modular forms.

[5][6] Together with Winfried Kohnen, she has proved upper bounds on the first sign change of Fourier coefficients of cusp forms,[7] generalizing the work of Siegel.

Selective Public Service: Choie has received several awards such as "The best Journal Paper Award (2002)" from the Korean Mathematical Society, "Kwon, Kyungwhan" Chaired Professor (2004) at Pohang University of Science and Technology, "The best woman Scientist of the year" award (2005) from Ministry of Science and Technology, "Amore-Pacific The best Women in Science and Technology" (2007), KOFWST (Korea Federation of Woman's Science and Technology Association) and the "2014 Distinguished research" award from Ministry of Education of Korea.

[4] Choie became the first female mathematician as member of the Korean Academy of Science and Technology in 2018.,[1] retrieved 2018-12-22.

She was the first female mathematician who received (2018) the academic award of Korean Mathematical Society.