If neutrinos are massive, there will be neutrino oscillation.
The history and status of neutrino oscillation experiments are summarized.
The main parts of this dissertation include three topics on different aspects of neutrino oscillation and neutrino masses.
The second topic is about neutrino oscillation theory in quantum field theory(QFT).
These results imply that there are neutrino oscillations, this means that neutrino has mass.
