Chen Yuan was said to be composed and intelligent in his youth, and not even his attendants could tell his emotions easily.
When soldiers under the command of the Sui general Han Qinhu (韓擒虎) entered the crown prince's palace, Chen Yuan's staff largely fled, but Chen Yuan, said to be then a teenager, himself solemnly sat within his hall to wait for the soldiers to enter, attended only by Kong Boyu (孔伯魚).
During the reign of Emperor Wen's son Emperor Yang of Sui, Chen Yuan was made the governor of Fuhan Commandery (枹罕, roughly modern Linxia, Gansu).
By the time that Sui fell and was replaced by Tang dynasty, however, he was back in Chang'an, and he served as a mid-level official early in the reign of Emperor Gaozu of Tang.
He died early in Emperor Gaozu's reign (618-626), but the exact year is not known.