The Maja plant is a green plant originating from tropical and subtropical regions of America, which is a plant from the Rutaceae family. The benefits of the Maja plant are many. All parts of the tree have been found useful. Pakcoy mustard is a vegetable plant that is needed by humans to meet their daily needs. The need for the vegetable market, especially Pakcoy mustard, has increased from year to year. Fertilizing plants is redundant to replace nutrients transported by plants, especially if the soil used for plant cultivation has a low fertility level, one of which is by utilizing the fermented Maja fruit waste, where the waste can be used as liquid organic fertilizer containing elements. macro and micronutrients needed by plants. This study aims to determine the effect of giving Maja fruit fermentation waste to the growth of mustard Pakcoy and to determine the best concentration for the growth of mustard Pakcoy. The method used in this study was an experimental method using a one-factor completely randomized design study (CRD) with concentrations of 0%, 10%, 20%, 30%, and 40% respectively 4 times with 5 treatments. The parameters observed in this study included plant height, number of leaves, root length, wet weight, dry weight, and abiotic factors. The research data were analyzed using analysis of variance (ANOVA), then if there was a significant difference, the LSD test was continued at 5%. The results showed that giving Maja fruit fermentation waste with a concentration of 40% affected increasing the wet weight of Pakcoy mustard with an average value of 82.50 grams. Keywords: Pakcoy mustard, maja fruit fermented waste, organic fertilizer.