Abstract: 【Objective】To analyze response of soil nutrient of red soil and microbial community to sugarcane-duck symbiosis,and to reveal micro-ecological mechanism of sugarcane-duck symbiosis on sugarcane growth and soil improvement by analyzing soil nutrition and microbial diversity,so as to provide theoretical basis on application of sugarcane-duck symbiosis in red soil sugarcane planting areas.【Method】Three treatments were set up in a field in situ experiment:sugarcane monoculture,sugarcane-duck symbiosis and meat duck rearing. Soil was collected from 0-20 cm of rhizospheric soil of the sugarcane monoculture and sugarcane-duck symbiosis treatments and from 0-20 cm of the meat duck pure rearing at the sugarcane maturing stage. Then soil nutrients,enzyme activities and bacterial community diversity of different treatments were measured and compared. 【Result】Sugarcane-duck symbiosis reduced ammonium nitrogen content in soil and increased invertase activity in soil highly significantly(P<0.01,the same below)compared with sugarcane monoculture.Alpha diversity analysis showed that the Chao1 index and Shannon index of soil bacterial community diversity were sugarcane monoculture>sugarcane-duck symbiosis>meat duck rearing. Bacterial groups detected in each sample belonged to 44phyla and 1079 genus. Species community composition analysis showed that Actinobacteri,Proteobacteria,Chloroflexi,Acidobacteriota,Bacteroidota and Myxococcota were dominant bacterial communities in the red soil sugarcane planting areas of Guangxi,enjoying high relative abundance. Gaiellales,JG30-KF-CM45,Gaiella,Xanthobacteraceae,67-14,Vicinamibacterales,JG30-KF-AS9,Roseiflexaceae,Gemmatimonadaceae,Bacillus,TK10,Sandaracinus,Vicinamibacteraceae,Rokubacteriales,Micromonosporaceae were dominant bacterial groups at genus level. Sugarcane-duck symbiosis increased the relative abundance of JG30-KF-AS9 significantly compared with sugarcane monoculture.【Conclusion】Sugarcane-duck symbiosis not only changes available nitrogen nutrients,but also increases soil invertase activity significantly. However,it does not change inter-rhizosphere soil bacterial community significantly in the short term.