In this project we have discussed about the modeling and simulating of sulfur recovery process. Claus process is the base of all sulfur recovery methods. So, at the first we have discussed about the Claus process. Then we have modeled the furnace because it is too important. The kinetic reactions that take place in the furnace, hasn't been known. So, the macroscopic modeling was chosen. This assumption causes to error over the calculations. But the calculation results that include conversion percentage, furnace temperature, dimensions of furnace and the amount of lost heat , can be used as sub-theoretical and simple model. At the last part, sulfur recovery process has been simulated by use of HYSYS package in the static and dynamic state. Static results are too close to fact. Due to lack of sufficient information, dynamic results aren't assessable. Lastly, we have studied about the effects of most important parameters on the process efficiency.