He gained popularity in idol dramas Green Forest, My Home (2005), Wayward Kenting (2007), Fated to Love You (2008), and My Queen (2009) and had a frequent collaboration with Doze Niu, who directed Monga (2010), earning Juan the 47th Golden Horse Award for Best Actor.

His grandfather, a seasoned veteran, transitioned from military service to a civilian role as the secretary of the board of directors at China Medical University.

[1] In 2002, when he accompanied a friend to an audition, he was chosen for his first showbiz gig in Penny Tai's music video for "Once Fell In Love" (愛過), after which he signed up with model agency Catwalk Entertainment.

Ruan made his acting debut in the 2004 TV drama Michael the Archangel, where he plays the role of a talented but moody dancer with an eerie and feminine aura.

[3][2] It wasn't until 2007, when Juan starred in Doze Niu's idol drama Wayward Kenting (2007) that his acting began to receive positive notices.

[9] After the service, on 5 March 2013, Juan announced that he will be opening a talent management agency (together with Doze Niu and Lee Lieh).

[15] In 2023, Juan enjoyed a career revival for his role in the sleeper hit action thriller The Pig, The Snake and The Pigeon.

Upon entering showbiz, Ethan Juan began a relationship with his then-manager, Chang Te Lin, who is 12 years his senior, until he fell for his Green Forest, My Home co-star Esther Liu in 2005.

In 2008, Shao revealed Juan's sexual preferences to a gossip magazine and claimed that he had been seeing her and Tiffany Hsu at the same time for nearly a month.

[16][17] In 2007, the relationship between Juan and Tiffany Hsu was made public by paparazzi photographs of them on a beach date in Kenting.