Rivers can absorb certain amounts of contamination relying on different factors such as: river discharge, the primary conditions of the river, the river depth, discharge and the river viscosity of the offloaded wastes in the river. From parameters of water quality point of view, it is recom-mended to determine some parts of the river which are lower than the standard level in order to find out the critical parts and suitable alternatives for simplifying the critical points. According to the above- mentioned topics, it is essential to identify the parts of the river which do not have standard conditions and also to determine the sources of pollutions that highly influence such conditions and to explore appropriate solutions. This essay provides the effect of polluting sources on the changes of dissolved oxygen and temperature in Ghezel-Ozen River based on the gathered qnalitative and qnalititative data. Since the required information is extensive for being modeled by QUAL2E software and the main effect of temperature parameters on line creatures and the influence of the dissolved oxygen on water quality originating from variety of pollutions. The results of simulating Ghezel-Ozen River imply the suitable oxygen condition and tempera-ture along the modeled river and Shahrud River is its auxiliary branch. Furthermore the fluctua-tions of water temperature in the discharge crossing the river and its effects on the temperature variations and finally dissolved oxygen and discusses the managing and controlling methods of river contamination.