Abstract
An elementary particle "neutrino" was born in Pauli's conjecture 70 years ago. Its study has made remarkable contributions to establishing the weak interactions and the electro-weak unification theory. Recently much interest has been directed to investigating the intrinsic properties of the neutrinos and important experimental results on their masses and mixings were obtained. This article introduces several experiments that have made break-throughs in neutrino physics. Also presented is a personal view of what should be done in future to further develop neutrino physics. This article is devoted to Professor Koshiba's 2002 Nobel Prize in physics.
