This article describes a study of a possible measurement at the CMS detector of the  CP-parity  of the Higgs boson  \Phi  using angular correlations in the  \Phi \to ZZ \to e⁺e^-\mu ⁺\mu ^- process, which is a ``golden plated channel''  for Higgs boson searches at LHC. It will be shown that a measurement of the  \xi -parameter describing a generalised  \Phi  ZZ coupling, which determines CP-parity of the Higgs boson, will be feasible at CMS. The precision of the measurement is sufficient for determination of  CP-parity of the Higgs boson, in particular to distinguish between the scalar and pseudoscalar Higgs bosons.

PACS numbers: 14.80.Cp