Abstract: The coastal area in Mamuju Regency, West Sulawesi Province has a very large mangrove ecosystem potential if it is utilized and managed properly to improve the welfare of the community. Therefore, in sustainable management efforts, it is necessary to know the condition of mangrove forests in the coastal area of Mamuju Regency. Based on this, a research was conducted to determine the condition of the mangrove ecosystem, namely the density of mangroves with the line transect method and the line transect plot in the form of a square with a size of 10 m x 10 m, and the mangrove canopy cover with the hemispherical photography method, then the photos were analyzed using a device. ImageJ software and Microsoft Excel.