An observation that Hall effect in the mixed state can have a sign opposite to that in the normal state has been reported for some conventional superconductor since 1960th. The discovery of a Hall effect sign change in the most of high-Tc cuprate superconductors [1] stimulated a new interest to this anomalous behavior. Various theoretical models have been proposed to explain the sign change of the Hall resistivity in the mixed state [2] but the origin of this phenomenon remains controversial. Transport properties of quasi-two-dimensional electron-doped Nd2-xCexCuO4+δ (x=0.14; 0.15; 0.17 and 0.18) single crystal films (B || с, J || ab) with different degree of nonstoichiometric disorder δ are investigated in magnetic fields up to 9T at T=(0.4 - 4.2)K. An analysis of normal state Hall coefficient RH n dependence on Ce doping takes us to a conclusion about the coexistence of electrons and holes in this nominally electron-doped cuprate system. Due to ARPES results [3] the two types of carriers may originate from electron like and hole like parts of the Fermi surface in cuprates. The evolution of the Hall coefficient value in the normal state above the upper critical field Bc2 is traced with a variation of Ce doping. It is found that low temperature normal state Hall coefficient RH n is negative for underdoped (x=0.14) and optimally doped (x=0.15) films, positive for highly overdoped (x=0.18) films and has RH n ≅ 0 for slightly overdoped (x=0.17) films in accordance with previous results for normal state RH of Nd2-xCexCuO4+δ T > Tc. As in the most of cuprates we have found an anomalous change of the Hall effect sign in the mixed state just below Bc2: from negative to positive for x=0.14; 0.15 and from positive to negative for x=0.17; 0.18. We have analyzed the Ce doping dependence of the normal state Hall coefficient in optimally reduced Nd2-xCexCuO4+δ single crystal films and, on the grounds of this analysis, have recruited a two-carrier model for describing of the mixed state Hall coefficient. Our scheme is based on a Drude model for normal state and on a semi-phenomenological Bardeen-Stephen model [4] for the mixed one modified by coexistence of electrons and holes. In analogy with [5] we have proposed that two types of carriers have rather different superconducting gaps and thus different upper critical fields Bc2 i, i = 1, 2 for electrons and holes, respectively. We have found also that for optimally doped (x=0.15) samples annealing in vacuum leads to an essential increase of the normal-state Hall coefficient due to removing of the interstitial apical oxygen and delocalization of the charge carriers. As for the mixed state we have seen that the amplitude of anomalous Hall peak quickly dropped with the increase of the degree of disorder (from optimally to non optimally reduced film) and for the most disordered film no sign reversal of the Hall effect in the mixed state have been observed. This work was done within RAS Program (project N 01-2-006-13394) with partial support of RFBR (grant N 12-02-00202). [1] S.J.Hagen, A.W. Smith, M. Rajeswari et al., Phys. Rev. B 47, 1064 (1993). [2] E.H.Brandt, Rep.Prog.Phys. 58, 1465 (1995), section 7.5. [3] N.P. Armitage et al., Rev. of Modern Physics 82, 2421 (2010). [4] J. Bardeen, and M.J. Stephen, Phys. Rev. 140, A1197 (1965). [5] J.E.Hirsch, F.Marsiglio, Phys.Rev.B 43, 424 (1991).