Byul's first album was released in 2002, with the interestingly-titled single "December 32nd" marking her debut in the entertainment industry. A song of waiting for a lost love (who promised he would be back before the end of the year), it became very popular (as it was released in December of that year). The subsequent singles from the album, though, did not achieve much popularity and Byul took a break from the music scene.

After taking one-year hiatus for vocal training, Byul released her eponymous second album, in March 2005. Her first and only single from the album was entitled "안부", a duet with ballad singer Na Yoon Kwon . Both the album and the single initially sold poorly. The song "I Think I Love You", however, was later used as the theme song for the Korean television drama Full House . The album enjoyed modest success when the drama became a hit domestically and internationally, and Byul's first two albums were subsequently released in China .

However, the title song "눈물샘" (literallyLachrymal Glands) was very popular, thus extending Byul's career. A followup single ("Cupid") was released, but it was promoted for a short amount of time, and Byul soon went on a break. She re-emerged in November to release a digital single, with the title물풍선 (12월 32일 그 이후), orWater Balloons (After December 32), alluding to her debut song, thus making it a sequel song of sorts.

In April 2007, she then released her fourth album, entitledHer Story. In 2008, she released a best-of album,The Best, with the lead single "A Glass." The album also includes a duet with Rain entitled "How I Love You," as well as "Feeling Good Today" featuring MC Mong and a duet with Na Yun-kwon entitled "How Are You."

, her fifth album, would be released the following month. Teaser posters were distributed in 7-11 stores.

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Korean albums

• Byul Vol. 1 - December 32 (2002)
  1. 12월 32일 (December 32)
  2. 왜 모르니 (Why Don't You Know)
  3. 별의 자리 (A Star's Place)
  4. 여기까진거죠 (Up to Here?)
  5. Don't Leave Me
  6. 바보같이 (Like An Idiot)
  7. 얼마나 사랑하는지 (How Much I Love You) (feat.비)
  8. 마음과 다른 말 (Saying Something Different From What Your Heart Feels)
  9. 그가 멀어질 때 (When I Am Further Away From You)
  10. 잊을 수 없네요 (I Can't Forget You)

• Byul Vol. 2 - Star (2005)
  1. 별 (別) (Star)
  2. 다른 사람 (Another Person)
  3. 안부 Byul (별) (Safety)
  4. 내 남자의 여자친구 (My Guy's Girlfriend)
  5. Saving My Best For You
  6. 이젠 내게 (Now to Me)
  7. 나쁜 저주
  8. 2 + 1
  9. 각자의 길 (Our Own Ways)
  10. 고마워할게요 (I'll Be Thankful)
  11. I Think I
  12. I Love You
  13. 나를 봐요 (Look At Me)
  14. 끝 (End)
  15. 안부 [Bonus Track] [Instrumental]

• Byul Vol. 3 - Lachrymal Glands (2006)
  1. 아무렇지 않게 (As nothing)
  2. 눈물샘 (Fountain of tears)
  3. 괜찮은 오늘 (feat.MC 몽)
  4. 우린
  5. 슬픈 건망증
  6. 큐피트
  7. Forever love
  8. 그대라는 사람은
  9. Stay by my side
  10. 버려야 할 것들
  11. 만나러 가는 길 (feat. Double K)
  12. 곁에서만 들리는
  13. 설레임

• Byul Vol. 4 - Her Story (2007)
  1. 미워도 좋아
  2. 연애의 정석 (Feat. Tk)
  3. 열한번
  4. 물풍선(12월32일 그 이후…)
  5. 세상의 반 (Feat. Hoody)
  6. 단꿈 (드라마 `오버더레인보우` Ost)
  7. Yes I Am
  8. 투정
  9. 잊혀진 것들에 대해서
  10. 서툰 기대
  11. 마음이 (영화 `마음이` Ost)

• Byul Vol. 5 - Like A Star: Primary (2009)
  1. 6년동안
  2. 행복하자
  3. 드라마를 보면
  4. 안녕
  5. 화풀어줘
  6. 허밍 (Feat.테이 Tei)
  7. 니가 떠난다 (Feat.박장근 Park Jang Keun)
  8. 울리지마
  9. 비키니
  10. I Love U
  11. 말해요
  12. Kiss Day
  13. Hymn

• SBS Gayo Daesang New Artist Award (2002)

1. Kim, Hyeong-woo. 별 새앨범 재킷 공개 ‘섹시-성숙미 발산’ (Byul's New Album Jacket Revealed, Radiates "Sexy Maturity"). Newsen January 30, 2009. Retrieved January 30, 2009.
2. "상꼬맹이' 하하, 유부남된다..별과 11월30일 결혼". Star News. http://star.mt.co.kr/view/stview.php?no=2012081413351189090&type=1&outlink=1. Retrieved 4 September 2012.