Sedimented land in mangrove forests is formed because the process of continuous sedimentation occurs naturally so that primary succession will occur in the area. The aim of the study was to determine the composition and pattern of zonation of mangrove vegetation that had been carried out on the sedimented land from Cilacap Donan. The study was conducted using a survey method, and sampling using a 1x1 meter squared plot for seedlings, shrubs and herbs. Size 5x5 meters for poles and size 10x10 meters for trees.

The results showed that there were several soils sedimented land , 2 sedimented were taken as samples. In sedimented land  1 for seedlings, shrubs and herbs are the most dominant is Acanthus illicifolius with IVI = 47.93%. The most dominant pole is Avicenia marina with IVI = 39.06%. For the most dominant tree is Rhyzophora mucronata with IVI= 34.13%.

In sedimented land 2 for seedlings, shrubs and herbs are the most dominant is Deris trifoliata with IVI = 48.15%. The most dominant pillar is Avicenia marina with IVI = 38.67%. The most dominant tree is Avicenia marina with IVI = 36.40%.

Tidal conditions and physical chemical properties that are not too much different cause the composition of mangroves on sedimented land 1 and sedimented 2 to approach similarity.

The zoning pattern is not formed significantly, but grouping occurs in several types, starting from the edge to the land.