Abstract: The 2015 Nobel prize in physics was awarded to Japanese physicist Takaaki Kajita and Canadian physicist Arthur B. McDonald, for the discovery of neutrino oscillations, which shows neutrinos have mass. This is the only new-physics phenomenon beyond the Standard Model of elementary particles, which alter our understanding of the physical world. In this article, history of the neutrino oscillation discovery was reviewed. We shall introduce the experimental results and theoretical explainations of the solar and atmospheric neutrino oscillations,the recent progresses in reactor and accelerator neutrino experiments, and discuss the future prospect of neutrino oscillations.