Morphology in Segara Anakan Lagoon has been actively changing for years which including all of morphology unit. Data in 1900s show that the width of lagoon changed significantly from 6,868 hectares to become 1,800 hectares reported in 1998. In accordance with the width and the depth changes caused by high rate sediment supply, the new mainland had been formed to be additional one to coastline and the bars morphology unit was followed by expansion of mangrove pioneer. Analysis was carried out using aerial photograph and geographical information system (GIS) application. Result of the analysis to show tidal flat morphology unit was one possessing most significant change including its patters, width and direction