The european part of Turkey, the Thrace region, is of agricultural and industrial importance for the country and hence irrigational and industrial water demand drastically increases, whereas most of the rivers in the region have no flow in summer. Two gauged hydrological basins are studied in order to analyze the following streamflow characteristics of the region: Randomness, jump, trend, and best-fit probability distribution. Selected gauging stations are found with random annual streamflow data for a 40 year observation period (1961-2000). No jump is observed in the annual mean streamflow time series of the rivers; however, the presence of insignificant negative trends is indicated by the trend test. Results for the probability distribution goodness-of-fit test show gamma distribution to be the best fit distribution for the rivers.