The present invention provides a kind of excellent prevention or medicine of inflammatory diseases. Contain prevention or medicine of the thymidine phosphorylase inhibitor as the inflammatory diseases of effective component (wherein, what thymidine phosphorylase inhibitor is the chloro- 6- of 5- (2- imido grpup Pyrrolizidine -1- base) methyl -2,4 (1H, 3H) when the situation of hybar X or its salt, inflammatory diseases do not include inflammatory bowel disease disease).本發明提供一種發炎性疾病之優異之預防或治療藥。含有胸苷磷酸化酶抑制劑作為有效成分之發炎性疾病之預防或治療藥(其中，於胸苷磷酸化酶抑制劑為5-氯-6-(2-亞胺基吡咯啶-1-基)甲基-2,4(1H,3H)嘧啶二酮或其鹽之情形時，發炎性疾病不包括發炎性腸疾病)。
