Eun-jeong mostly known as Eunjung was born in Seoul, South Korea. Her mother, a graduate of Ewha Womans University, is a former piano teacher who works as Eun-jeong's agent. While attending seventh grade, Eun-jeong started taekwondo lessons and won three different competitions. Her mother made the decision to quit teaching and manage Eun-jeong's career upon her high school graduation in 2007. Later that year, Eun-jeong enrolled in Dongguk University, where she took performance courses. She is an only child and has been quoted as explaining, "My mother had me 10 years after she was married to my father, which seems more hurtful. Upon watching several famous performers in the past, she wanted to become an actress. Now that I have, she is very pleased I have acting as a priority. She believes her original prayers were answered."



In 1995, when Eun-jeong was seven years old, she participated in the "Little Miss Korea" pageant and won. That same year, she appeared in the youth drama "신세대 보고서 어른들은 몰라요" ("Sinsedae Bogoseo Eoreundeureun Mollayo"), which aired on television.[4] Afterwards, she had several minor roles in movies and Korean dramas, along with being cast in a handful of commercial films.



Eunjung's acting debut was in Hello, My Teacher! where she appeared as a high school student who was unfairly cheated out of a grade which could have put her above the top 40 point.



She appeared in SG Wannabe's music video "Gasiri" ("가시리") from their 2007 album Story In New York. Later, she would also be seen in FT Island's music videos of "Thunder" ("천둥"), "Only One Person" ("한사람만"), and "A Man's First Love Follow Him To The Grave" ("남자의 첫사랑은 무덤까지 간다").



She starred in Davichi's music video "Time, Please Stop" ("시간아 멈춰라"; "Sigana Meomchwora") which was released on May 6, 2010. 



Her first major role after joining T-ara came in Coffee House, which aired on SBS from May 17, 2010 to July 17, 2010.



In July 2010, Eunjung was cast in her first movie role for the thriller White (화이트).[12][13] Directed by Kim Gok and Kim Sun, filming began in November 2010.[14] The film was released to South Korean cinemas on June 9, 2011.



Eunjung, along with 2AM's Jo Kwon and CN Blue's Jung Yong Hwa, had guest starred on Episode 7 of the popular SBS variety show Running Man which aired on August 22, 2010.



She starred in the drama Dream High where she played the role of Baek-Hee. She later took part in historical dramas such as King Geunchogo and Queen Insoo.



In March 2011, she joined the cast of MBC's We Got Married and started full-fledged shooting before her virtual husband was confirmed. Eunjung was paired up with actor Lee Jang-woo who met each other for the first time at the start of Season 3, replacing the leaving YongSeo couple. Their couple names include "WooJung Couple" meaning "friendship" named according to their friendly nature, and "Campus Couple" named because they had found out that they were both in the same acting major at the same college, Dongguk University. The couple was featured in the music video for ZIA's "The Way I Am", released on September 29, 2011.



T-ara’s agency Core Contents Media revealed that Eunjung is confirmed for the drama “Five Fingers”.



From the group's debut in July 29, 2009 until September 2010, she was the second leader of T-ara. She and Jiyeon are the only two members of T-ara to be trained in acting. Instead, the two switched over to singing despite their original intentions