Abstract: This study investigated various factors affecting the removal of nitrogen and phosphorus from aquaculture wastewater. Specifically, how hydraulic retention time (HRT), herbaceous halophyte(Sesuvium portulacastrum), biomass carbon, water flow pattern, seasonal and environmental factors affecting the removal of total phosphorus (TP), total nitrogen (TN), and ammonia nitrogen (NH₄⁺-N) in 12 constructed wetland systems. The results show that by setting up the HRT in the range of 0 to 3 days, the removal rates of nitrogen and phosphorus increased with the increase of HRT, meanwhile the conductivity and pH of effluent increased gradually. When the HRT was 3 days, S. portulacastrum plants could improve the removal rates of TN, TP, and NH₄⁺-N to a certain extent. Adding biomass carbon into zeolite-based system could significantly improve the removal rates of TN and NH₄⁺-N, however, the biomass carbon played a negative role in the removal of TP in the system. Among the four water flow patterns used in this study, the upward vertical-flow wetland systems resulted in the best removal rates of nitrogen and phosphorus. Conductivity, dissolved oxygen, and pH were significantly and positively correlated with the removal rate of TN and TP, while pH was significantly and positively correlated with the removal of NH₄⁺-N. The removal efficiencies of TN and TP were the highest in summer, and the efficiency for removal of NH₄⁺-N was the highest in spring. The water temperature was positively correlated with the removal of TN, TP and NH₄⁺-N.