The dynamic of growth and nutrient (N and P) absorption of Coix lacryma-jobi Linn.in constructed wetland (CW),as well as the effect of constructed wetland harvest on N,P absorption in eutrophic water were studied.The results revealed that,in Summer and Autumn,especially in August,C.lacryma-jobi could obtain higher biomass and N,P accumulations,thereby achieving the most efficient purification; from the breeding value point of view,N,P contents could be improved by the appropriate increase of harvest times of C.lacryma-jobi,while too many harvest times was inappropriate to the wastewater purification by C.lacryma-jobi and the nutrients accumulation.So,C.lacryma-jobi should be harvested completely in August during its growth period,and twice-3 times of harvests was appropriate.