Abstrak Pemberian rosella (Hibiscus sabdariffa Linn) diharapkan melindung hepar tikus dari kerusakkan akibat stres oksidatif pada keracunan karbon tetraklorida (CCl 4). Senyawa yang sering dijadikan petunjuk adanya kerusakan tersebut adalah malondialdehid (MDA). Rosella mengandung vitamin C, flavonoid, polifenol dan beta karoten. Tujuanpenelitian ini adalah menentukan pengaruh pemberian ekstrak rosella (Hibiscus sabdariffa Linn) terhadap MDA dan aktivitas katalase tikus yang terpapar CCl 4. Ini adalah penelitian eksperimental dengan desain Post test Only Control Group Design. Sampel 24 ekor tikus Strain Wistar berumur 2-3 bulan, berat 150-200 gr. Sampel diambil secara acakdan dibagi 4 kelompok terdiri dari kelompok kontrol negatif, kontrol positif (CCl 4), perlakuan 1 (CCl 4 dan ekstrak rosella 250 mg/kg bb) dan perlakuan 2 (CCl4 dan ekstrak rosella 500 mg/kg bb). Pemberian CCl 4secara oral dosis tunggal, setelah 24 jam kemudian diberi ekstrak rosella secara oral selama 14 hari. Data dianalisis dengan uji Anova, tingkatkepercayaan 95%.Pemberian ekstrak rosella secara statistik didapatkan perbedaan yang signifikan rerata kadar MDA dan katalase antar kelompok (p < 0,05). Disimpulkan bahwa ekstrak rosella dapat menurunkan kadar MDA dan meningkatkan aktivitas katalase tikus yang terpapar CCl 4. Kata kunci: karbon tetraklorida, MDA, katalase, rosella Abstract Administering roselle (Hibiscus sabdariffa Linn) is expected to protect rat liver from damage caused by oxidative stress in CCl4 poisoning. Rosella contains vitamin C, flavonoids, polyphenol and beta carotene. Compounds which was often used as marker of the damage caused by free radicals wa MDA. The objective of this study was to determine the effect of extracts of roselle (Hibiscus sabdariffa Linn) on MDA and catalase activity of rats exposed to CCl4. Experimental research design with Post test Only Control Group Design. Samples of 24 male Wistar Strain rats were 2-3 months old. weighing 150-200 gr. Samples were taken at random and divided into 4 groups consisting of a negative control group, positive control (CCl4), treatment 1 (CCl4 and roselle extract 250 mg / kg bw) and treatment 2 (CCl4 and roselle extract 500 mg / kg bw). CCl4 was given a single dose orally, after 24 hours, the subjects were given rosella extract orally for 14 days. Data were analyzed by ANOVA with a confidence level of 95%. Rosella extract obtained statistically significant differences of MDA and catalase levels among groups (p <0.05). It can be concluded that the rosella extract can reduce levels of MDA and increase the activity of catalase mice exposed to CCl4. From the research it can be concluded that the rosella extract can reduce levels of MDA and increas the activity of catalase mice exposed to CCl4. It is needed further research on the toxicity of extracts of rosella and organ damage caused.Keywords: carbon tetrachloride, MDA, catalase, rosella