  We analysis the sea quark densities, based on the constituent quark model. To
perform a direct fit with available experimental data, the parameterized
Inverse Mellin technique is used. The calculation is extended to the NLO
approximation for the singlet and non-singlet cases in DIS phenomena. We employ
the approach of complete RG improvement(CORGI) where one is forced to identify
and resum to all-orders RG-predictable ultraviolet logarithm terms which truly
build the Q-dependence of QCD observable. The results are compared with the
standard approach of perturbative QCD in the ${\bar{MS}}$ scheme with a
physical choice of scale. The results in the CORGI approach indicate a better
agreement to the data.
