Delima water apple is a local variety from Demak which has been SOP related to water apple cultivation since 2010. The function of the water apple SOP is as a reference for GAP of delima water apple farming. The purpose of this study was to determine the level of application GAP, find out the factors related to the level of application GAP, and identify constraints on the application of GAP on delima water apple farming in Wonosalam District, Demak Regency. The research was conducted in three villages of delima water apple production centers, including Sidomulyo, Mranak, and Kendaldoyong Villages during 2018. Data collection was conducted through interviews with 72 randomly selected farmers. The level application of delima water apple GAP was analyzed by the Likert Scale Scoring method, while the factors associated with the application of GAP were analyzed by the Spearman Rank Correlation method. The descriptive analysis is used to identify constraints to the application of GAP on delima water apple farming. The results of the analysis show that the level application of GAP on delima water apple farming in Wonosalam District is in the medium category. Factors in the number of plants, land area, availability of capital, income, and input costs were positively related to the level application of GAP on delima water apple farming. The constraints on the application of GAP for delima water apple are knowledge, capital, and technology that are still not owned by farmers.