The coast of Modung District is one of the areas in the south of Bangkalan Regency that is vulnerable to coastal erosion. This study focuses on optimizing coastal land in the vulnerable Modung District of Bangkalan Regency to address coastal erosion while enhancing agricultural productivity, economic valuation of mangrove forests, and minimizing soil erosion. Using Geographic Information System (GIS) analysis, Total Economic Value (TEV) assessment of mangrove forests, and the Universal Soil Loss Equation (USLE) model for soil erosion estimation, the research employs goal programming techniques to optimize land allocation. The findings reveal valuable insights: agricultural productivity ranges from 57.07 to 5892.39 tons/Ha in the Modung coastal area, while the economic valuation of mangrove forests is estimated at IDR 55,748,386/Ha. Soil erosion potential is identified, with agricultural and residential areas facing 0.53 and 2.01 tons/ha/year, respectively, while mangrove areas experience 0.06 tons/ha/year. The total potential soil erosion loss in the area is estimated at IDR 11,941,375,649. The optimization analysis presents a scenario allocating 3897.85 Ha for agricultural use, 788.63 Ha for settlements, and 120.51 Ha for mangrove conservation. This approach aims to enhance agricultural productivity, mitigate soil erosion, and conserve mangrove areas, contributing to coastal land conservation efforts.