The life of Zengren, or Monk Shi from the White Grass Quarter of the Longxing Temple in Lingzhou, appeared in the Song Biographies of Eminent Monks. He practiced asceticism by copying scriptures in his own blood in order to make merits. He also composed a text titled Treatise on the Damages of three Teachings, which did not survive and no details are available. However, among Dunhuang manuscripts, there are six copies of the Record on his legend, which seem to come from the compilation of late generations based on his early writing Treatise on the Damages of three Teachings. This study will reconstruct his writing by reading these Dunhuang manuscripts and offering annotations. It will also examine the virtues of copying scriptures and related issues on the blood copying practice. Combining the Buddhist doctrines and the apologetic institutions, as well as the literary style, this study will shed new light on the Buddhist culture of Dunhuang manuscripts.