The use of l-9substituted phenyl)-5-methyl-2-(IH) pyridine in the manufacture of medicaments for treating fibrosis in organs or tissues. It indicates that l-(substituted phenyl)-5-methyl-2-( 1H) pyridine can inhibit the cells produced by various ECM, and their effect is higher than pirfenidone. Therefore, this type of compounds can be used as active ingredient for preparing the antifibrotic agent in organs and tissues.