Debut : 6 November 2005
Fan club : E.L.F. (Everlasting Friends)
Balloon colour : Pearl Sapphire Blue
Name : Choi Si Won
Hangul : 최시원
Position : Vocalist, Face of The Group
D.O.B : 10 February 1987
P.O.B : Seoul Gangnam, South Korea
Height : 185 cm
Blood type : B
Religion : Christian
Siblings : 1 younger sister (Choi Ji Won)
School : InHa University (Major: Physical Education)
Hobbies : Playing drums, Singing, Dance, Acting, Speak chinese, Taekwondo
Act in :-
1. Precious Family (2004)
2. 18, 29 (2005)
3. Charmel Boy (2005)
4. Spring Waltz as Park Sang Wook (2006)
5. A Battle of Wits (2006)
6. Hyangdan (2007)
7. Attack on the Pin-up Boys as Siwon student body president (2007)
8. Oh! My Lady as Sung Min Woo (2010)
9. Athena Goddess of War as Kim Joon Ho (2010-2011)
10. Glamorous Challenge (2011)
11. Poseidon as Kim Sun Woo (2011)
12. I Am: SMTOWN LIVE WORLD TOUR in Madison Square Garden (2012)
13. The Lord of Dramas as Kang Hyun Min (2012-2013)
14. Helios (2015)
15. She Was Pretty as Kim Shin Hyuk (2015)
16. The Man In The Mask as Thief (Ep.1) (2015)
17. Byun Hyuk's Love as Byun Hyuk (2017)
