Abstract: Abstract: Pistia stratiotes L., one types of aquatic plants, has been commonly known as the water lettuce in the arum family. The absorption of Pistia stratiotes L. has been successfully used for the ecological treatment to dispose the urban wastewater in recent years. However, it is still lacking on the removal performance and driving factors of antibiotic resistance genes (ARGs) in the livestock and poultry wastewater. In this study, a systematic investigation was made to evaluate the purification effects and driving factors of ARGs during floating plant Pistia stratiotes L. treating the dairy farm wastewater. An analysis was also made to clarify the overall removal performances and occurrence regularity of ARGs in the different types of wastewater. Furthermore, the measurement was conducted to determine the diversity and structural difference of microbial communities in the ecosystem after different treatments. Thus, the driving factors of ARGs were obtained to combine the microbial communities, mobile genetic elements, and environmental factors. Three kinds of actual wastewaters were set in the dairy farm, including the raw water, anaerobic pond and oxidation pond wastewater. Sixteen kinds of ARGs and three kinds of MGEs were selected to widespread in the wastewater of three dairy farms. The results showed that the excellent overall purification effect of Pistia stratiotes L. was achieved during this time. A positive removal effect was found in the absolute abundance of the most ARGs in the wastewater. The best performance of Pistia stratiotes L. was also achieved for the removal of blaOXA-1 in the raw water, the oxidization pond, the low-concentration anaerobic tank in strB, and the high-concentration anaerobic tank, with the removal effect of 3.66. 3.51, 4.07, and 1.27, respectively. In the raw water, oxidation pond wastewater, and low-concentration anaerobic pond wastewater, the absolute abundance (lg value) of ARGs after the treatment of Pistia stratiotes L. decreased by 0.25 (ermA and fexA) to 3.66 (blaOXA-1), 0.08 (blaTEM-1) to 3.51 (strB), and 0.09 (fexA) to 4.07 (strB), respectively, after the treatment of large flies. By contrast, only 9/16 of the ARGs showed the positive removal for the high concentrations of anaerobic wastewater. There was also the variation in the microbial community in the wastewater after the treatment of Pistia stratiotes L. The high-throughput sequencing demonstrated that the microbial diversity and abundance increased significantly in the different wastewaters. The relative abundance of Proteobacteria and Firmicutes decreased dramatically, but that of Bacteroidetes and Actinobacteriota increased, in the wastewater, which was quite different, compared with the microbial community under plant-free treatment. The microbiome increased by 1.64 times in Flavobacterium at the genus level. The RDA analysis of the main drivers of ARGs showed that the interpretation rates were 9.6%, 6.0%, 7.0%, and 5.1%, respectively, combining with environmental factors with the changes in the ARGs in the combination with the dominant phylum and genus (Hydrogenophaga, Flavobacterium, Bacillus, and Gemmobacter). The network analysis concluded that there was the greatest correlation between the relative abundance of ARGS and the environmental factors in the TP and microbial communities in the Proteobacteria. The mantel test also demonstrated that there was a very significant relationship between the microbial dominant bacteria and individual ARGs. Therefore, the Pistia stratiotes L. can be expected to treat the livestock and poultry wastewater. The removal of ARGS by Macros was also driven by the microbial and environmental factors. The removal effect and driving factors of ARGS can greatly contribute to a theoretical basis for the prevention and control of ARGS pollution in the livestock and poultry sewage. The finding can provide a strong reference to promote the green and sustainable development of plant ecological treatment.