ABSTRACT: Indonesia as the largest archipelagic country in the world has a marine economic potential of up to US$ 1,338 billion per year, but its utilization requires a sustainable approach through the implementation of Blue Accounting as an instrument for marine resource management that integrates economic, social, and environmental aspects. This study aims to analyze the practice of Blue Accounting in the fisheries sector in West Kutai Regency, identify the factors that affect its implementation, evaluate its contribution to the sustainability of the marine economy, and identify challenges and opportunities for its implementation. The research used a descriptive qualitative method with an in-depth interview technique with seven related structural officials as key informants selected by purposive sampling, carried out for nine months at the West Kutai Regency Fisheries Office. The results of the study show that the implementation of Blue Accounting is still in the development stage with the formulation of sustainable policies having been implemented well, the community-based POKMASWAS system has been formed in six coastal sub-districts, but monitoring technology has not been optimal. Aquaculture production increased by 15.7% to 2,777 tons with the achievement of the target of 106.8%, accompanied by a reduction in poverty of 0.53% and open unemployment of 0.58%. The main inhibiting factors include limited supervisory human resources, lack of operational budget (1.5% of the total budget), and limited technological infrastructure. Blue Accounting contributes positively to the sustainability of the marine economy through increasing productivity, diversifying businesses, and improving the welfare of coastal communities. It is recommended to increase budget allocation, strengthen human resource capacity, develop real-time monitoring systems, and diversify funding sources to optimize the implementation of sustainable Blue Accounting.