This study elucidated the therapeutic effect of H. pluvialis crude extract and its fractions (astaxanthin, astaxanthin ester, and β-carotene) in treating hepatic fibrosis via decreasing ECM components and its deposition, regulating oxidative stress and MMP9/TIMP1 as well as finally activating Kupffer cell. The gene discussed is MMP9; the disease is Hepatic fibrosis.