  We discuss the possibilities of the simultaneous determination of the
neutrino masses and the evolution of dark energy from future cosmological
observations such as cosmic microwave background (CMB), large scale structure
(LSS) and the cross correlation between them. Recently it has been discussed
that there is a degeneracy between the neutrino masses and the equation of
state for dark energy. It is also known that there are some degeneracies among
the parameters describing the dark energy evolutions. We discuss the
implications of these on the cross correlation of CMB with LSS in some details.
Then we consider to what extent we can determine the neutrino masses and the
dark energy evolution using the expected data from CMB, LSS and their cross
correlation.
