  We apply the Maximum Entropy Method to determine valence quark distributions
of the neutron at a low scale $Q_0^2$. At the initial evolution scale $Q_0^2$,
there are no sea quark and gluon distributions except for that of the three
valence quarks (udd). Using the DGLAP equations with parton-parton
recombination corrections (nonlinear effect), we obtain the neutron structure
function $F_2^{\rm n}$ at any high scale $Q^2$. The predicted structure
function ratio $F_2^{\rm n}$/$F_{2}^{\rm p}$ is approximatively consistent with
the world DIS data of proton and deuteron targets, if the uncertainties caused
by model-dependent corrections are taken into account. Furthermore, our
obtained $F_2^{\rm n}/F_{2}^{\rm p}$ ratio basically agrees with BONuS
experimental results after considering both the contamination from the nucleon
resonances around $x\gtrsim 0.4, 0.5, 0.6$ and the contribution of systematic
uncertainties. The predicted $F_2^{\rm n}/F_{2}^{\rm p}$ and $u/d$ ratios under
the limit of $x\rightarrow 1$ are compared with the theoretical calculations.
Finally, we check that the parton distributions of proton and neutron
approximately satisfy isospin symmetry in this work.
