Neutrinos have a finite mass as observed from neutrino oscillation experiments such as
Kamiokande. The massive neutrinos imprint characteristic signatures in large-scale
structure of the universe because neutrinos have a large free-streaming velocity
compared to ¡Ècold¡É dark matter (CDM) where CDM is usually assumed to have a negligible
thermal velocity. For this reason, we can use observables of large-scale structures,
such as the number of massive clusters and weak lensing, to constrain the neutrino
mass. In this talk, I describe the effects of massive neutrinos on cosmology, and then
the current status of neutrino mass constraint from cosmological surveys.