Jing Hao (??) was a Chinese mountain-and-river (shan shui, also known as landscape) painter and theorist of the Five Dynasties and Ten Kingdoms period. As an artist, he made great contributions to Chinese landscape paintings. He created the Northern Landscape painting style and strongly influenced the tradition of Northern Song painters. In his writing, A Note on the Art of the Brush (called Bi Fa Ji), he proposed a painting technique of allowing the heart to follow after the brush. Jing Hao was undoubtedly one of the most important founding figures of mountain-and-river paintings. However, there were few literatures describing this masters lifetime. Where did he came from and where did he live? It is a question mark in history. In this paper, we discover Jing Haos lifetime by recognizing an uncertified/unknown painting signed with the name Jing Hao, and we verify the authenticity of the painting according to several steps. First, we study the authenticity of the painting by recognizing the kind of paper, backing, and painting skill. Second, we find out the relationships between Jing Haos writing and the painting. Finally, we verify the authenticity of the signature and seals on the painting. In conclusion, we find that it was highly probable that the painting was done by Jing Hao in A.D. 921.