The research aims to assess the water quality of Alkaber Alshemaly River through field and laboratory study included identifying each of the following variables: dissolved oxygen (DO), carbonic biochemical oxygen demand(CBOD), and the river temperature, electrical conductivity (Cond). We have also modeled two important water-quality variables (DO and BOD) using QUAL2K river and stream surface water-quality model. The studied part of the river is an area located between 16 October dam and Alegnsa, where we have five sampling sites. The field and laboratory study showed increase in D.O values to reach the highest values in the months of March, April, January and February, and the lowest values were recorded in the months of July, August, September in all sampling sites. As a final result all D.O values in all locations were higher than the minimum allowable 5 mg/l. For CBOD5 the highest values were recorded in the months of June, July and August, and the lowest values were recorded in the months of March, December, and January at all of the sites studied. In the case of D.O and CBOD, the research showed a good correspondence between the model results and field values in the months of March, January, and November, but the correspondence was relatively less in August. In general, the study showed the possibility to use the QUAL2K model to simulate rivers-water quality in Syria.