The liquid wastes collected from residential, commercial, and industrial areas and sent to a central location for treatment by a sewerage system are referred to as municipal wastewater.(Adams et al. 1999). Wastewater discharged from households, companies, and establishments is referred to as "domestic wastewater." (METCALF - EDDY, (2014) n.d.). The chemical, physical, and energy-intensive procedures used to recycle water that has been considered unfit for its primary use (e.g., drinking, washing, and chemical reactions) due to a shift in its fundamental properties are referred to as wastewater treatment. Biological oxygen demand (BOD), chemical oxygen demand (COD), pH, and other properties are examples. (CHEREMISINOFF 2019). Engineers design wastewater treatment plants that provide treated wastewater that complies with water quality permit requirements. Instruments could be used to forecast potential effluent quality in streams and lakes with several dischargers due to the technical nature of the plants that generate the effluent. In recent years many studies about the simulation of wastewater treatment plants focused on how the simulation will improve the performance of the treatment process. No such studies were done in Jordan so far, so it will be a big step to start improving the performance of the wastewater treatment plants in Jordan using the simulation software, since Jordan treats over 90 percent of the wastewater (USAID, 2018), and use 107.4 million cubic meters of treated wastewater for the irrigation (Food and Agriculture Organization of the United Nations, 2005), Wastewater treatment is essential in Jordan. The thesis will focus on modeling and simulation of wastewater treatment plants using at least two software. and detect the differences between this two software. next to make a comparison between each software and the reality to check the similarities and what can be applied in real and what cannot be applied. and run several scenarios about the changes that may occur in the plant: including the flowrates and the characteristics of the influent wastewater and the operational parameters.