The study was carried out to evaluate the species composition and abundance of zoobenthos in the rotational rice-black tiger shrimp farming model toward organic standards in Thoi Binh district, Ca Mau province. Water quality, sediment and zoobenthos samples were collected at 18 sites including 12 rice-shrimp farms and 6 canals. The rice-shrimp farms were divided into 3 groups: group N1 (conventional model), group N2 (probiotic supplement) and group N3 (probiotic supplement + additional feed). Each group of N1, N2 and N3 was repeated four times. The study was conducted from February to December 2022 with 4 sampling periods, including 2 times in the shrimp crop (beginning and end of the crop) and 2 times in the rice crop (beginning and end of the crop). The results showed that the water environment and sediment factors were suitable for the zoobenthos development. Contents of total nitrogen (TN), total phosphorus (TP) and total organic matter (TOM) in the sediment were relatively high and did not differ significantly between sampling locations. The silt and clay percentages in the sediment were 95.0±2.6% and 5.0±2.6%, respectively. The study identified a total of 36 zoobenthos species belonging to 36 genera, 26 families, 18 orders, 5 classes, and 3 phyla. At the collection sites, the zoobenthos species number ranged from 8 to 25 species. Average density and biomass of zoobenthos varied from 162±238 to 5,848±3,391 ind m-2 , and 8.2±11.4 to 565.0±360.8 g m-2 , respectively. In the rice-shrimp farms, the species composition, density and weight of zoobenthos in the shrimp crop were higher than that in the rice crop. Gastropoda dominated in all N1, N2 and N3 groups, while Bivalvia accounted for the highest proportion in canals of the study area. The average Shannon-Wiener (H'), Simpson diversity (D) and Pielou evenness (J') indices ranged from 0.3 to 1.9, 0.1 to 0.8 and 0.2 to 0.9, respectively, showing zoobenthos diversity from low to medium at the collection locations. The zoobenthos species composition and density were significantly correlated (p < 0.05 and p < 0.01) with environmental factors and sediment characteristics in the study area. The use of probiotic and feed supplement in the rotational rice-black tiger shrimp farming models contributed to creating a natural food source for shrimp to grow and develop.