He is well known as a member of boy band H.O.T.. Also he is an executive of SM Entertainment since 2005 and the chief producer of Kreation Music Rights's label Smashhit since 2023.

He made his debut on-screen appearance as a backup dancer together with future bandmate Moon Hee-joon for labelmate singer Yoo Young-jin.

Kangta eventually decided to become a singer with Moon and three others, Jang Woo-hyuk, Tony An, and Lee Jae-won to form H.O.T.

Later in March, the heroine Seong-so (played by Lim Eun-kyung) was cast as the beloved singer Ga Jun-oh in Jang Sun-woo's film "The Second Coming of a Match Girl" and made a cameo appearance.

In 2004, he starred in a drama called Magic Touch of Fate together with Taiwanese actors and actresses, Ruby Lin and Alec Su.

A poll was issued over the internet, allowing only people outside of Korea to vote.2005 Mnet KM Music Video Festival Kangta also acted in his second Chinese drama,[10] Love in the City 2.

In March Kangta was announced to be playing a supporting role in JTBC's 2012 drama Happy Ending as Kim So-eun's love interest.

It is about the true life story of Lieutenant Lee Jong-myung, who lost his legs in a land mine explosion near the demilitarized zone, in June 2000, when he saved fellow soldier, Sul Dong-seob from the minefield.

[13] After two years and five months of hiatus from the entertainment industry due to Korean military service, Kangta released Chinese Single Breaka Shaka.

In March 2014, Kangta, alongside labelmate BoA, was appointed as a de facto creative director of S.M.

After a three-year musical hiatus, the new song "Cough Syrup" was pre-released on SMTOWN LIVE "Culture Humanity" on January 1, 2021.

[20][full citation needed] SM Entertainment announced that Kangta would begin preparations for his twenty-fifth anniversary project throughout 2021.

[25] On August 17, 2022, it was announced that Kangta would be making a comeback[a] on September 7 with his fourth studio album Eyes on You, marking his first almost two decades (since 2005).

[30][full citation needed] And in 2024, he expanded his field by working on songs with a number of singers, discovering various producers.

[32][full citation needed] After planning for years, Kangta worked with his celebrity friends Shin Hye-sung from Shinhwa and Lee Ji-hoon to form the project group named 'S', an initialism for 'Supreme'.

Their title track, "I Swear" was written, composed, and arranged by Kangta while Shin wrote the English lyrics.

Kangta's unique music style and the trio's harmonious voices will create beautiful ballads that will satisfy the fans".