The distribution of arsenic(As) in shallow groundwater of eastern Chancheng District in Foshan City as a function of season and water table was investigated, and the influence of hydrochemical factors on the As distribution was discussed. The groundwater samples were collected from 20 sites in dry season and 9 sites in wet season. As concentrations in 20% groundwater samples exceeded value of the WHO guideline(10 μg/L), and the highest As concentration of 23.5 μg/L occurred in dry season. It is observed that groundwater As concentration decreased with the increase of depth of water table in dry season, and were generally higher in wet season than that in dry season, indicating that ground surface As might be one of the main sources for shallow groundwater As in study area, especially in wet season. Groundwater As concentration in study area had significantly positive correlation with the concentration of Fe, Mn, NH4, F, and COD, and was positively correlated to p H, but negatively correlated to Eh and K, indicating that reductive dissolution of Fe and Mn(oxy)hydroxides might be one of the main control mechanisms for groundwater As mobilization, while p H and F also played an important role in controlling the groundwater As mobilization in study area. The distribution of arsenic (As) in shallow groundwater of eastern Chancheng District in Foshan City as a function of season and water table was investigated, and the influence of hydrochemical factors on the As distribution was discussed. The groundwater samples were collected from 20 sites in dry season and 9 sites in wet season. As concentrations in 20% groundwater samples exceeded value of the WHO guideline (10 μg / L), and the highest As concentration of 23.5 μg / L occurred in dry season. It is observed that groundwater As concentration decreased with the increase of depth of water table in dry season, and were generally higher in wet season than that in dry season, indicating that ground surface As might be one of the main sources for shallow groundwater As in study area, especially in wet season. Groundwater As concentration in study area had significantly positive correlation with the concentration of Fe, Mn, NH4, F, and COD, and was positively correlated to p H, but negatively co rrelated to Eh and K, indicating that reductive dissolution of Fe and Mn (oxy) hydroxides might be one of the main control mechanisms for groundwater As mobilization, while p H and F also played an important role in controlling the groundwater As mobilization in study area .