Analysis Water and sediment characteristic and its changing pattern in Gan river using the monitoring data of annual runoff and suspended sediment transport from 1957 to 2010 of Waizhou Hydrological Station in Gan river. The results showed that:(1) Gan River Annual Runoff in nearly 50 years experienced increased first and then decreased with the change process, since 1998 in recent ten years, a significant decrease appear.(2) The sediment into the lake of Gan River in nearly 50 years has also experienced the first increased and then decreased with the change process, the annual sediment discharge of Gan River reduced greatly since 1991.(3) Ganjiang annual sediment discharge and annual runoff showed a double distribution, the relation of annual sediment discharge and in size the correlation between volume and peak flow product even more close. The annual sediment yield was significantly higher than the accuracy of empirical formula, empirical formula without peak flow, more practical.