Background: Kersen leaf is one of the plants that can be used asa medicinal plants and has the potential to lower triglycerides because they contain flavonoids and tannins. This study was used to determine the effect of ethanol extract of kersen leaf (Muntingia calabura L.) on reducing blood triglyceride levels in hypercholesterolemic male white rats (Rattus norvegicus). Methods: This study was a laboratorium experimental study with a pre and post test with control group design. The subjects were 30 male white rats (Rattus norvegicus), body weight ±200 grams, aged 3-4 months, and divided into 5 groups with random sampling. The groups were negative control (K-) was given high-fat diet and PTU without anytreatment, positive control (K+) was given high-fat diet and PTU with simvastatin treatment, (P1) fwas given high-fat diet and PTU with ethanol extract of kersen leaf dose 100 mg/kgWB, (P2) was given high-fat diet and PTU with ethanol extract of kersen leaf dose 200 mg/kgWB, and (P3) was given high-fat diet and PTU with ethanol extract of kersen leaf dose 400 mg/kgWB. Triglyceride levels were measured before and after applying treatment. This study was held for 4 weeks. Triglyceride level was measured using the GPO-PAP method. The data was analyzed using normality test with Shapiro-Wilk, homogenity test with levene test, triglyceride test after high fat diet and simvastatin and after high fat diet and ethanol extract of kersen leaf with Anova test. Result: The ethanol extract of kersen leaf dose 100 mg/kgWB, 200 mg/kgWB and 400 mg/kgWB are found effective on reducing blood triglyceride levels with a mean reduction in the first treatment of 112,83 mg/dl, 98,20 mg/dl, 89,92 mg/dl and in the second treatment of 106,71 mg/dl, 93,95 mg/dl dan 76,87 mg/dl. Statistical analysis using one-way ANOVA showed p<0,05, which determines a significant difference of triglyceride levels among each group. Conclusion: The ethanol extract of kersen leaf dose 100 mg/kgWB, 200 mg/kgWB and 400 mg/kgWB are effective on reducing blood triglyceride levels in white rats (Rattus norvegicus). Dose 400 mg/kgWB is found to be the most effective dose in triglyceride reduction.