AlPO4, was modified with NH4, Mo and Ca by treatment with Al-2(SO4)(3)center dot 18H(2)O, CaCO3, (NH4)(6)Mo7O24 center dot 4H(2)O, (NH4)(2)HPO4 and 25% aq. NH3 soln. at Ca2+:PO43- mol. ratios 0.6 +/- 0.4:1 and pH 7 +/- 1. The anticorrosive properties of the pigments were detd. by an electrochem. noise method. The pigment consisting of Al3+:Ca2+:Mo6+:NH4+:PO43- mole ratio 0.9:0.4:0.004:0.58;1 showed the highest corrosion resistance.