By selecting the research region located in Houzhai River basin of Puding County in central karst region of Guizhou Province

water samples of perennial spring water in forest area

farming area

rural resi-dential area and town residential area were collected and analyzed to investigate the influence of urbanization on the N and P concentrations in shallow groundwater and the change of water quality. Results show that the concentrations of NO-3and NH+4in shallow groundwater were within 1.18～43.6 and 0.017～0.290mg/L

respectively

of which the concentrations of NO-3and NH+4in the shallow groundwater of forest area

farm-ing area and rural residential area were in the range of the classⅢ water quality

but the concentration of NH+4in town residential area was beyond the classⅢ water quality. The concentration of total P was within 0.012～0.682mg/L

but in rural and town residential areas

the concentration of total P exceeded the limit of water quality. The contents of N and P in groundwater increase in the process of urbanization

which ex-erts a significant impact on groundwater quality in the karst hilly area.