CP violation effects of the Higgs stem from not only CP-violation interactions but also an ambiguous defined CP state. The two CPV sources are coherently studied based on an effective Higgs Lagrangian. The constraints from unitarity limits for $WW$ and $ZZ$ scatterings are proposed to restrict Higgs couplings to weak gauge bosons. Five interesting cases are classified in terms of CPV sources to investigate the Higgs CP properties. The allowed ranges are shown from fitting results to the signal strengths of the Higgs measured by ATLAS and CMS.