This paper shows that the neutrino does not violate the law of parity conservation, P and CP violation comes from the vacuum. If we take vacuum into account, the law of P.C. T conservation is universally true. 本文证明了中微子并不破坏宇称守恒定律和P与CP的破坏都来源于真空,如将真空也计算在内,则P、C、T守恒定律都普遍成立。