Abstract: In view of the fact that the components of compound flooding are complex，at present，it is difficult to simultaneously determine any component concentration by using analytic method of single component sample，the derivative spectrographic method is proposed.By using this method，the concentration of KY，XCC and AOS in the compound system are determined，and its accuracy and the major influencing factor are probed.The experimental result indicates that the concentration of KY，XCC and AOS are separately in 2～100mg/L，3～60mg/L and 2～100mg/L，the corresponding wave length separately in 229.5，208.5，235.5nm.Its derivative spectrum obeys the Bill law，and three extinctions have the very good additive property.The obtained data are analysed by the least squares method，thus the concentration of three kinds of chemical agents is separately determined.Without being separated and depurated，the multi-component solution concentration can be determined simultaneously and accurately.One new technical method is proposed to simultaneously determine the multi-component solution concentration.

Key words: derivative spectrographic methods, least squares method, compound flooding, concentration, simultaneous determination