As a result of dedicated studies, the present inventors succeeded in discovering, for the first time, that fibrogenesis could be suppressed at the physiological tissue level by inhibiting sulfation at position 4 or 6 of GalNAcc, which is a sugar that constitutes sugar chains. Furthermore, the present inventors conducted studies using various disease model animals, and as a result, successfully demonstrated that inhibitors of sulfation at position 4 or 6 of GalNAc had therapeutic effects on diseases caused by tissue fibrogenesis (tissue fibrogenic disorders).