Background: The purpose of this study was to analyze the effect of ethanolic extract of chayote on oxidative stress of obese white rats of wistar strain (Rattus novergius Sp.) induced by a high fatty diet. Method: This study uses a type of experimental laboratory research design post-test randomized controlled group. Researchers measured the effect of treatment (intervention) on the experimental group by comparing the experimental group with the control group. The sample was obtained by a simple random sampling method. Experimental sites and other research materials can be said to be homogeneous. This study will measure MDA levels as a biomarker of oxidative stress, IL-6 as a sign of inflammation, bodyweight as obesity, leptin levels as a biomarker of appetite and lipid profile levels. The research was conducted at the Biomedical Laboratory of FK UMI and started the acclimatization process, giving experimental animal surgery treatment at the animal house of FK UMI Results: The results of the study concluded that the effect of chayote ethanol extract can affect oxidative stress which has potential as anti-obesity and hypolipidemia and antioxidants. Conclusion: Ethanol extract and chayote fruit fraction have antiobesity