Abstract: In the study of the color reactions of Ni(Ⅱ),Co(Ⅱ) and Zn(Ⅱ) with the color reagent 2-(6-methyl-2-benzothiazolylazo)-5-diethylaminobenzoic acid (abbreviated as MBTAEB) in hexamine buffer of pH 6.6 and in the presence of ethanol separately,highly sensitive reactions were observed giving molar absorptivities of εNi646=1.49×105L·mol-1·cm-1,εCo650=1.32×105L·mol-1·cm-1 and εZn630=7.7×104L·mol-1·cm-1,respectively.But the absorption spectra were seriously overlapped making the direct determinations impossible.The problem of spectral-overlapping was solved by the application of AKC matrix analysis,a simple,rapid and selective method for the simultaneous determination of Nickel(Ⅱ) Cobalt(Ⅱ) and Zn(Ⅱ) ions in a same solution without the necessity of separation was made possible.