The objective of this study was to examine the effect of rosehip (Rosa rugosa Thunb.) ethanol extract (RRE) on liver fibrosis in mice and the underlying molecular mechanisms. RRE has no acute oral toxicity, and the MTD in mice is 46.14 g/kg. Histopathological analysis showed that RRE significantly ameliorated inflammation, necrosis, and apoptosis of hepatocytes and collagen deposition caused by CCl4. Further assays indicated that RRE significantly suppressed the production of MDA while markedly increasing the levels of SOD and GSH in the liver. The AST, ALT, IL-6, IL-1β, TNF-α, HA, LN, PCIII, and IVC levels in serum were decreased by RRE. Transcriptome analysis shows that RRE significantly upregulates the PPAR signaling pathway. The RT-q PCR results further confirmed the RRE up-regulating Pparγ, Rxrα, and Plin5 in the PPAR signaling pathway. The Western blot and immunohistochemical results indicate that RRE upregulated PPARγ, RXRα, and Perilipin 5 while downregulating α-SMA and COL1A1 expression. The results indicate that RRE can ameliorate liver fibrosis in mice by upregulating the PPAR signaling pathway.