Caisim are a vegetable commodity that is widely loved by people in Indonesia. Caisim are easy to cultivate and can be eaten fresh or processed into a wide variety of foods. One of the decreases in the production of caisim crops is due to the disturbance of plant disturbing organisms (OPT), namely armyworms (Spodoptera litura L.) To control these caterpillars, farmers generally use chemical pesticides. In an effort to reduce the use of chemical pesticides, one of them is by using vegetable pesticides, namely ketapang leaves. Ketapang leaves (Terminalia catappa L.) have the potential to be used as a vegetable insecticide because they contain active ingredients such as alkaloids, flavonoids, saponins, and tannins. This study aims to determine the effect of ketapang leaf extract and determine the effective dose of ketapang leaf extract in controlling grayworm pests (Spodoptera litura L.). This research was carried out at the Production Laboratory of the Department of Agroecotechnology, Faculty of Agriculture, Lambung Mangkurat University, Banjarbaru from March 2022 to May 2022. This study used a Complete Randomized Design with 5 (five) treatments and 4 (four) tests. The treatments tried were b0: without ketapang leaf extract (control), b1: ketapang leaf extract 4.5%, b2: ketapang leaf extract 9%, b3: ketapang leaf extract 13.5%, and b4: ketapang leaf extract 18%. The results showed that the application of ketapang leaf extract (Terminalia catappa) had a significant effect in controlling the armyworm pest (Spodoptera litura) on caisim plants in the b1 treatment with a concentration of 4.5% (4.5 ml of extract + 95.5 ml of aquades) which can be deadly above 50% of armyworm larvae (Spodoptera litura L.) so that it can be recommended as basic information in the use of vegetableinsecticides.