Abstract： In order to detect the origin and content of manganese in groundwater of the Zhujiang River Delta, the authors sampled and analyzed 352 groundwater samples and 13 surface water samples. The results show that manganese content varies from the undetected level to 8.32 mg/L in groundwater of the Zhujiang River Delta, with the average manganese content being 0.34 mg/L and the standard-exceeding rate being 49.4%. The manganese content of groundwater that exceeds the standard exists in nine cities of the Zhujiang River Delta. There exists an obvious positive correlation between the manganese content and TDS, COD, and HCO3ˉ of groundwater as well as a notable negative correlation between the manganese content and Eh of groundwater in this delta area. The distribution of manganese in groundwater is closely related to the extent of industrialization and recharge, runoff and discharge conditions of this area. Redox environment, pH condition, total dissolved solids in groundwater, property of the cover, groundwater flow conditions, and aquifer media are major factors responsible for the distribution of manganese in groundwater of the Zhujiang River Delta.