Table 2 and Figure 5 indicate that Kyllinga brevifolia Rottb. was initially the dominant plant in the reconstruction zone. Kyllinga brevifolia Rottb. adapts easily to moist conditions.Because there is a river channel across the bottom of the flood irrigation system, Kyllinga brevifolia Rottb. gradually grew up the slope from this region after reconstruction. Ageratum houstonianum Mill. whose vertical plant let height is much higher than Kyllinga brevifoliaRottb. became the most dominant species in the reconstruction within two months(Figure 5).