Öz The reaction of 11-tungstophosphate with cobalt(II) has been used for indirect spectrophotometric and atomic absorption determination of phosphorus. Excess of cobalt is separated from mixed heteropolyanion with use of cation ion-exchange resin KU-2 in Na+-form. Cobalt can be determined after destruction of a heteropolyanion or as a complex with α-nitroso-β-naphtol, or on measuring of absorption of cobalt atoms using flame air-acetylene (λ=240,7 nm). The perspectives of this method has been shown for increasing of sensitivity and expansion of number of elements, which can be determined