”tyi bar” was used in mifwu's (米芾) ”bao chang dai fang luh” (寶章待訪錄)and shen kuo's (沈括) ”meng chi pi tan” (夢溪筆談). It meaned the postscript of painting and calligraphy. ”ou yang wen chung kung chuan chi” (歐陽文忠公全集) established ”tsa tyi bar lei” (雜題跋類). ”sung wen chien” (宋文鑑) established ”tyi bar lei” (題跋類). ”wen chang pien ti” (文章辨體) and ”wen ti ming pien” (文體明辨) defined for ”tyi bar” (題跋). They meaned the postscript of book and writing. Now the definition of ”tyi bar” (題跋) is not sure. My thesis offered a reasonable definition by studying the development of the art's postscript and the book's postscript.