In 2010, Heo left DSP Media, who managed him as part of SS501, and moved to B2M Entertainment, with bandmate Kim Kyu-jong, to pursue his solo career.

[10] Heo Young-Saeng was born on November 3, 1986, in Gochang County Jeollabuk-do, South Korea as the only child of his family.

[18] Heo hosted SS501's radio program SS501's Youngstreet on SBS along with fellow member Park Jung-min from May 1 to August 21, 2006.

[19] He was forced to leave the program due to a throat condition that required laryngeal surgery, and bandmate Kim Kyu-jong took over as DJ.

[27] However, they stopped their activities as a group for a period of time as Park Jung-Min and Kim Hyun-Joong were given solo projects for the Grease musical[30] and the Boys Over Flowers series,[31] respectively.

[32] They also contributed to the Boys Over Flowers soundtrack with "내 머리가 나빠서" (Because I'm Stupid),[33] and appeared as a cameo in episode four, performing their track, "U R Man".

[42] In 2009, Heo started contributing soundtracks to television dramas, which includes "눈물을 지워가" (I Erase Tears) from Friend, Our Legend[43] and "사랑해요..미안해요.." (I Love You..

[45] In launching his solo career, he and Kim held a joint fanmeeting, Kyu Jong & Young Saeng Story in Seoul on December 4, which continued in Hong Kong, Japan and countries across Asia.

[46][47] He was scheduled to launch his solo singing career on April 28, 2011, but had to postpone because he pulled the ligaments on his right hand during a dance practice.

[48] He was also scheduled to guest star on SBS's Good Sunday variety show Running Man, on May 8, 2011, but due to his injury, he appeared only briefly to hand out a mission.

[49] Heo's solo debut mini album, Let It Go, was released on May 12, 2011, which features Spica's Park Ju-hyun on the music video, and Kim Kyu Jong and Hyuna on "Rainy Love" and "Let It Go" tracks respectively.

[51] On November 9, 2011, Heo, along with other Korean and Japanese artists, performed at the Seoul Tokyo Music Festival 2011 at the Saitama Super Arena, Japan.

[53] On May 9, 2012, B2M Entertainment officially announced via Twitter that Heo, himself, participated in the planning process and production of his new mini album Solo.

[58] Together with Bada, Bobby Kim, and Jeon Soo-kyung, Heo was invited to be a guest judge on MBC's Birth of A Great Star 3 in January.

[64] On March 18, he released his third mini album Life containing four songs, including his music video entitled "The Art of Seduction".

However, B2M later announced that Heo's fanmeeting in Saeng Quito, Ecuador and Arequipa, Peru on August 22 and 24 respectively were cancelled due to lack of time for proper preparation.

The album contains five tracks about a man's regrets and painful memories for a past lover,[85] and his single, "Weak Child", featured Japanese actress Fujii Mina.

[88] On the side note, his fans from all over the world had donated a total of 1.23 tons of rice, 200 eggs, and 2,400 coal briquettes to be given to a Heo's chosen charity.

He was enlisted as a conscripted policeman for about twenty-one months after passing in late July,[6] which he has been preparing for after receiving the draft notice.

[90] During his training, he became one of the leaders of the troop[91] while enjoying his army life with his unit members, as told by his handwritten letter to his fans.

CEO of CI ENT shared that Heo Young Saeng will actively begin promotions in singing as well as acting in the near future.

His very first official schedule following his discharge was a fan meeting in Korea on August 29 at Sungshin Women's University's Woonjung Green Campus auditorium.

[93] According to CI ENT, "We are very pleased and honored that yesterday's (August 4) ticket open for Heo Young-saeng's fan meeting sold out.

They performed the musical at the Meijijao Theater in Tokyo Japan from December 13 to the 25th featuring Kim Hyung-jun and Heo as Kang Young-won and Han Min-ho respectively.

While, Hyun Joong and Jung Min were inactive at the time due to military service duty, CI Entertainment released a photo teaser for their comeback.

[95] The group held a concert at BLUE SQUARE Samsung Card Hall on March 19 and 20, 2016 entitled "2016 Double S 301 CONCERT〈U R MAN IS BACK〉IN SEOUL".

In Dec 2016, prior to Double S 301's comeback activities, Heo rose gained popularity from singing the song, 'I cannot forget' in the OST for 'Blow Breeze', on MBC Weekend Drama, released on December 3, 2016.