The present invention is related to use of nanoparticle containing tyrosin kinase inhibitor for the manufacture of pharmaceutical composition for ameliorating liver fibrosis. The present invention utilizes copolymers of polyethylene glycol and poly (D, L-lactide-co-glycolide) to form nanoparticle containing tyrosin kinase inhibitor, such as Sorafenib. The use of nanoparticle is non-toxic and can increase the stability and decrease the release of drug in blood circulation. The pharmaceutical composition is an injectable composition. The nanoparticle containing tyrosin kinase inhibitor of the present invention can effectively ameliorate liver fibrosis including decreasing extracellular matrix accumulation, suppressing hepatic stellate cell activity, shrinking of abnormal blood vessel, and lowering microvascular density in fibrotic liver; hence, is suitable for clinical application for the treatment of liver fibrosis.本發明係關於一種包覆酪氨酸激酶抑制劑之奈米粒子在用於製備改善肝臟纖維化之醫藥組成物的用途。本發明以聚乙二醇和聚乳酸聚乙醇酸的共聚物形成之奈米粒子包覆一酪氨酸激酶抑制劑,例如:索拉非尼,可增加該酪氨酸激酶抑制劑在血液循環中的穩定性、降低釋放速率,並且安全無毒性。該醫藥組成物係為一針劑。本發明包覆酪氨酸激酶抑制劑形成之奈米粒子可有效改善肝臟纖維化之現象,包括:減少纖維化肝臟中細胞外基質的累積、抑制肝星狀細胞之活性、降低該纖維化肝臟中新生血管之密度及管徑。故,可應用於臨床肝臟纖維化的治療。