  Suppose the geometrical explaination to the weak CP phase in quark sector is
also valid for neutrinos, the mixing and CP violation in neutrino system are
discussed. We find a larger $J_{CP}$ than $3\times 10^{-3}$ implys the
large-mixing solution for solar neutrino problem. In case of bi-maximal mixing,
we predict relative large CP violation with $J_{CP}$ larger than $10^{-3}$ in
neutrino system, except the third mixing angle approachs to 0 or $\pi/2$ very
closely.
