There are ongoing debates about cutting effects on the growth and wastewater purification of plants in constructed wetlands. This experiment was carried out in the Biological Park, South China Normal University from July 2010 to January 2011. Constructed wetlands (2m×2m×0.6m) were grown with Cyperus alternifolius to assess cutting effects on growth and wastewater purification. The growth rate of C. alternifolius remained high for the treatment (cutting) group during the entire experiment period but was low for the control (no cutting) group after November 2010. At the end of the experiment, accumulated aboveground biomass, nitrogen and phosphorus contents, and new tillers from July 2010 to January 2011 in the treatment group were higher than those in the control group, and C. alternifolius showed overcompensation growth. The chlorophyll content, net photosynthetic rate, transpiration rate and stomatal conductance in the treatment group were evidently higher than those of the control group. The average removal rates of TP, TN, NH₄-N and NO₃-N in the treatment and the control group were 77%, 84%, 64%, 72% and 65%, 67%, 55%, 63%, respectively, which were significantly higher in the treatment than the control group. The average removal rates of COD_cr and BOD₅ in treatment and the control group were 58%, 79% and 54%, 76%, respectively, which were not significantly different. These findings suggested that a positive effect of cutting on growth and wastewater purification of C. alternifolius in constructed wetlands, which may provide insightful information on the management of constructed wetlands.