en تخصصي Special پژوهشي Research paper <div style="text-align: justify;">&nbsp; &nbsp; &nbsp; &nbsp;In this paper an SIS epidemic model with saturated incidence rate and treatment func- tion is proposed and studied. The existence of all feasible equilibrium points is discussed. The local stability conditions of the disease free equilibrium point and endemic equilibrium point are established with the help of basic reproduction number.However the global stabili- ty conditions of these equilibrium points are established using Lyapunov method. The local bifurcation near the disease free equilibrium point is investigated. Hopf bifurcation condi- tion, which may occurs around the endemic equilibrium point is obtained. The conditions of backward bifurcation and forward bifurcation near the disease free equilibrium point are also determined. Finally,numerical simulations are given to investigate the global dynamics of the system and con rm the obtained analytical results.</div> Epdemic models, Local stability , Backward bifuraction ,Hopf bifurcation. 129 146 http://ijmsi.ir/browse.php?a_code=A-10-2878-1&slc_lang=en&sid=1 R. kamel Naji 10031947532846007456 10031947532846007456 Yes Department of Mathematics, College of Science,University of Baghdad, Baghdad, Iraq A. Adnan Thirthar 10031947532846007457 10031947532846007457 No Department of Mathematics, College of Science,University of Baghdad, Baghdad, Iraq