According to the description of greedy devil in a Manichean treaty, this paper maintains that a pottery Zhu unearthed at a site of Tang Dynasty in front of Kizil Grottoes should be an art piece showing male's sexual organ with devil face which was described in the treaty. It can be viewed as a direct reference to help iconically the believers understand doctrine better, especially those about sexual ideas. Therefore, it is such an iconical material that is valuable for us to understand the mental life of ancient Manichean believers.
