Eco enzyme is a liquid organic fertilizer that is environmentally friendly and can be used as an alternative in the use of fertilizers to help the growth and yield of green mustard. Eco enzyme can increase the content of nutrients in the soil and help the process of breaking down nutrients so that they can be absorbed by plants. The use of eco enzyme alone is not enough to meet the needs of nutrients in mustard plants, so the addition of nutrients using NPK is needed. This study aims to determine the effect of green betel leaf eco enzyme with various doses on the growth and yield of green mustard. This research was conducted from May to July 2023 at the Research and Experimental Garden of the Faculty of Agriculture, Fisheries and Marine Affairs, University of Bangka Belitung. This study used a non-factorial group randomized design with 9 levels of treatment testing, namely: E0 (-) = Control (Without eco enzyme and NPK fertilizer), E0 (+) Control (NPK fertilizer), E1 = 2 ml/L eco enzime + NPK, E2 = 4 ml/L eco enzime + NPK, E3 = 6 ml/L eco enzime + NPK, E4 = 8 ml/L eco enzime + NPK, E5 = 10 ml/L eco enzime + NPK, and E6 = 12 ml/L eco enzime + NPK, E7 = 14 ml/L eco enzime + NPK. Each experimental unit was repeated as many as 4 replicates so that there were 36 experimental units. Data were analyzed using ANOVA followed by Duncan Multiple Test (DMRT) to determine differences in each treatment at a significant level of 5% and 1%. The provision of eco enzyme gave a significant effect on the parameters of plant height, leaf width, leaf length and had no effect on the parameters of the number of leaves, fresh weight of plants, and root length. There is no dose that gives the best results, but the E4 treatment on average gives the best results on the growth and yield of green mustard.