We have studied the flux of galactic protons and helium nuclei measured at 1 AU along two consecutive solar activity cycles. We have correlated cosmic ray fluxes measured on IMP 8 satellite at low energy (50 - 300 MeV amu(-1)) with neutron monitor counts registered at Climax station (at energies above few GeV) during the period 1973 - 1995. We have found a systematic excess in the flux of the positive charged particles during the periods with positive solar magnetic field polarity (A > 0) with respect to the flux during the periods of negative polarity (A