This paper aimed to identify the determinants of bank net interest rate margins within the context of the Syrian banking industry. To achieve the objectives of the study the data has been collected from those commercial banks listed on the Damascus exchange stock (DES) during 2006-2010. The sample used in this study consists of a panel data set for sixe commercial banks. The empirical specification focuses on the reported net interest rate margin that is assumed to be a function of operation cost, owner's equity, loans-to-asset proxy, size factor, market share, growth rate, inflation factor, exchange rate. For testing purposes, panel data analysis is used by employing three alternative models to estimate the parameters of the model, the Pooled simple regression, the Fixed Effect Model and the Random Effect Model.