Abstract: Remote sensing technology had been widely applied in the river information extraction, and the water index and threshold algorithm, a kind of spectrum analysis way, were the dominant method. In spite of fast speed, the water index and threshold method could hardly consider effects of adjacent pixels, which may result in many tiny rivers channel and frag- mentation water, and then increases the workload of the subsequent processing. In order to simultaneously exploit spatial and spectral information of TM images, and overcome the shortcomings of the water index threshold, object oriented image seg- mentation technology was used to extract Jialing River channel of four time intervals, then RIVWIDTH tool was used to calcu- late the river central line and river width. Four indicators are used to verify the accuracy of the river extraction images in2007, which were mapping accuracy, user accuracy, Kappa coefficient, the complete degree, and the values for them were84%, 90%, 0. 91, 86%, respectively. At the same time, RIVWIDTH automatic channel extraction tool had high operational effi- ciency, high degree of automation. It was found that the accuracy of RIVWIDTH tool attained88% on the condition of relative error less than25%. The results showed that the model could accurately extract the channel of Jialing River, and removed most of the small patches.