High As groundwater has had a significantly negative impact on human health. Therefere, many scientists from different countries or regions have made great efforts on chemical characteristics of As groundwater and mechanisms of its occurrence. Based on comprehensive review of related literatures, this paper systematically summarized the worldwide overview of high As groundwater, groundwater As-enriched environment and As resource, analytic methods and technologies for As speciation, mechanisms of As mobilization, and strategies for drinking water safety in As-affected areas. States of the art of related studies mainly focus on As speciation of sediments in As-affected aquifers, arsenic mobilization mediated by microbes, application of isotopic techniques in recognizing As source and transfer, and technologies for As drinking water safety.