With a simple mathematical method the three-component-system eH3Ci (citric acid) + fAlCI3 + gNaOH was analysed and the formation of complexes between citrate and aluminium calculated. Mixtures of eH3Ci + fAlCI3, with e/f ratios from 0 to 2.5 were titrated with NaOH. For each titrated mixture which existed of eH3Ci + fAlCI3 the coefficient g(NaOH) was found from the inflection points of the titration curves. When the eH3Ci/fAlCI3 molar ratios were plotted against the corresponding molar ratios of gNaOH/fAlCI3, linear functions were obtained from which the following three dehydrated complexes were calculated : [Al3OHCi3]⊖ from the first inflection point at pH between 3.0-3.5, [Al3(OH)4Ci2]⊖ from the 2nd inflection point at pH between 3.8-4.8, and [Al10(OH)15Ci6]3⊖ from the 3rd inflection point at pH between 5.6-7.5.