Abstract: Based on the field survey in 2005〖KG-*2〗-〖KG-*7〗2006, the composit ion and spatiotemporal distribution of phytoplankton diversity in Futian mangrov e wetland of Shenzhen were studied, and the water body’s trophic state of the we tland was assessed by using Shannon-Wiener diversity index, Pielou evenness ind ex, Margalef abundance index, and dominance index. A total of 51 species (includ ing 1 variety and 9 unidentified species) belonging to 28 genera in 5 phyta were identified. The phytoplankton density in each season all reached 106 ind·L -1 or more. In terms of species number and quantity, diatom was dominant in th e phytoplankton community. Cyclotella caspia and Thalassiosira nordenskil di were the dominant species, while the other pollution-tolerance species suc h as Oscillatoria minima and Euglena pisciformis became dominant in some stations in summer and autumn. In contrast to the remarkable spatiotemporal var iation of species composition, a greater spatial but little temporal variation o f phytoplankton quantity was observed. Dominant species had remarkable spatiotem poral variation, but the simplicity was obvious. The four diversity indices pres ented more spatial variation, and the assessment with these indices showed that the water body’s trophic state of the wetland was at meso-eutrophic, and tende d to be eutrophicated. It was necessary to strictly control the wastewater disch arging and inland runoff into the mangrove wetland.

Key words: Economic fruit forest, Comprehensive management pattern, Ecological environment, Benefit