  We performed the measurement of the inclusive electron scattering off the
proton in the resonance region (W<2.5 GeV) at momentum transfer Q2 below 4.5
(GeV/c)^2 with the CLAS detector. The large acceptance of CLAS provided an
access to a large, continuous two-dimensional kinematic domain in Q2 and x,
allowing therefore an integration of the data at fixed Q2 over x-interval. The
covered x-interval at each measured Q2 value is sufficient for an evaluation of
the higher moments (n>2). From these data we extracted the structure function
F2 and, by including other world data, we studied the Q2 evolution of its
moments, Mn(Q2), in order to estimate the higher twist contributions. A similar
experiment with polarized proton target is completed at CLAS. These new data
allow an accurate determination of higher moments of the proton structure
function g1. A preliminary phenomenological analysis indicates an excess of the
higher twist contribution in the spin-dependent structure function with respect
to the spin-independent one.
