Objective To develop a spectrophotometry in tetra component complex system of A1-CAS-CTMAB-OP for the determination of aluminum in floured food.Methods The sample was processed by combustion and the content of aluminum in foods was determined by spectrophotometry with Al-CAS-CTMAB-OP as color system.Results A linear relationship between the aluminum content and absorbency was in the range of 0.04～0.32 ?g/ml with the regression equation equating to A =3.551 2x-0.005 34,the correlation coefficient was 0.997 6,the detection limit was 0.001 4 ?g/ml and the recovery rate was in the rang of 98.6%～ 103.2%.Conclusion This method has been applied successfully to determine the aluminum in floured food for its special features, such as simple,rapid and accuracy.