Prince Hyoseong (Hangul: 효성태자, Hanja: 孝成太子; d. 976), personal name Wang Imju (Korean: 왕임주; Hanja: 王林州) was a Korean Royal Prince as the oldest son of Taejo of Goryeo and Lady Cheonan. He was the older brother of Prince Hyoji and later married his half niece, only daughter of King Jeongjong and Queen Munseong. After supported Gwangjong's Kingship reinforcement plan, he and his other half brother, Prince Wonnyeong was killed in 976 by the released nobles when the King's abolition of the aristocratic deterrence was abolished.