In this talk I will discuss two phenomenological studies related to neutrino physics. The first one is about searching for the singlet charged scalar at the Large Hadron Collider, as the singlet charged scalar is known to be present in various radiative neutrino mass models. In the second part of the talk, I will focus on the cosmological aspects of neutrino physics, especially the gravitational clustering effects on cosmic relic neutrinos in the Milky Way, which are relevant for the upcoming detection of cosmic neutrino background.