Abstract: Groundwater arsenic poisoning in the Ganges drainage basin was found in the 1980s. Through a case study of the time-space evolution,ecological effects and causes of arsenic poisoning in the Ganges drainage basin,the authors point out that the regional ecological geochemical assessment now being carried out in China should learn a lesson from arsenic poisoning in the Ganges drainage basin,and especially we should pay attention to the Cd anomaly distribution along the Yangtze River,China. The relevant provinces along the Yangtze River should be considered as a whole in regional ecological geochemical assessment on Cd anomalies.