Research on the diversity of Macrozoobenthos on the coast of Mangkoso village, Barru Sub-district in Barru district. The purpose of this research is to determine the diversity of Macrozoobentos. This research uses the purposive sampling method in determining the location of research stations and plot making using the line Transect method. The research station consists of three stations, i.e., Station 1, Station 2, and Station 3. The results of the study found 20 species of Macrozoobentos consisting of 13 species from Klas Gastropoda, from Classis Bivalvia 5 species, Polychaeta 1 species and Crustacea 1 species to a total of 20 species (Fillum Mollusca), Cerithium dialeum species, Cerithium sp, Clithon faba, Clithon oualaniense, Clithon sp, Hebra corticata, Hebra sp, Littorina sp, Nassarius bimacularus, Nerita sp, Smaragdia rangiana, Tornatina coarctata, and Vitta sp. Class Bivalvia consists of Anadara sp, Epicodakia sp, Spondylus sp, Tellina mariae, and Tellina sp. While Class Polychaeta, each one species is Naineris and Uca sp. The composition of the species, the population density, the negation, and uniformity of the community macrozoobenthos that the Station 2 is higher than Stations 1 and 3. It is seen on the results of the diversity index (H′) of Macrozoobentos at Station 1 (0.92) and Station 2 (2.55). All three stations indicate that low diversity and environmental quality conditions are in a half-polluted state. The seawater’s quality around the coastal Mangkoso village, Barru District, needs the local government’s attention to reduce environmental pollution.