根据华北地区分布的 ３３ 个水化观测点的水氡观测资料，以半年为尺度对唐山７．８ 级地震前水氡的异常演化过程进行了研究，认为：唐山 ７．８ 级地震前水氡异常存在由外围向震中区演化的异常特征，且在唐山地震发生的短临阶段，水氡异常在唐山地区形成集中，异常强度最大 According to the observation data of water radon at 33 hydration observation stations distributed in North China, the anomalous evolution of water radon before the MS7.8 Tangshan earthquake was studied on a semi-annual scale. It is concluded that before the Tangshan MS7.8 earthquake radon There is an anomalous characteristic of anomalous evolution from the periphery to the epicenter. In the short and immediate phases of the Tangshan earthquake, water anomalies were concentrated in Tangshan area with the largest anomalous intensity