Abstract: A framework is basically established for the evaluation of sedmient optmial allocation in them a instream of Yellow River.The framework is built on the systemic,hierarchical,representative,quantitative and com parable principles,and includes six evaluation parameters amiing at both technologic and economic subobjectives in the spatial optimization of sediment allocations.The procedure of calculating the six evaluation parameters is proposed.The synthetic evaluation function is presented.As the result,a method for comprehensive evaluation of sedmient optmia l allocations in the mainstream of Yellow River is determined.The method is used to evaluate 12 existing schemes of sediment optmial allocations in the Yellow River,and a preferable scheme is identified.The scheme suggests the optimal compositions of sediment allocations,which are 41.0% held in reservoirs,18.0% for land formation in estuaries,17.8% discharged into deep seas,10.4% consumed by irrigation,6.9% for siltation to beaches,3.8% for silting of mainstream,and 2.1% for silting flood plains.