In middle July,2010,the largest flood since 2003 occurred in the Minjiang River Basin.The analysis on the genesis and composition of this flood shows that the strong rainfall process in the Minjiang River Basin is the direct cause,and this flood has significant influence on the largest flood of the upper Yangtze River in 2010 and plays a role in flood peak formation.We summarize the forecast practice of flood in 2010.It is concluded that in order to improve flood forecast accuracy,we should strengthen the analysis and research on storm-flood characteristics in the basin and better understand the genesis and characteristics of the flood,meanwhile,we should reinforce the communication and co-operation among the operators of large and middle hydropower stations in the basin.