One of the critical success factors in the performance of Constructed Wetlands (CW) is drain-operation of wastewater into the CW. The purpose of this study was to determine the performance of horizontal subsurface-flow constructed wetland (HSSF-CW) in Fe removal and raise pH of AMD with the difference operations of the wastewater flow. Two kinds of the HSSF-CW were planted with the Purun tikus (Eleocharis dulcis). Purun tikus is potentially as a biofilter due to its fast grow and adapt well to the flooded acid soils. The Model-A of HSSF-CW is operated in batch-flow while the Model-B is operated with continuous-flow. Dimensions of the HSSF-CW is 100 cm x 30 cm x 35 cm. Results showed that Fe-removal in the Model-B is greater (103.61 mg / day) compared to Model-A (37.69 mg / day) and the HSSF-CW Model-A is only able to raise pH as much as 0.92 units, while the HSSF-CW Model-B increases pH as much as 1.97 units. It can be concluded that the HSSF-CW Model-B has better performance as compared to the Model-A. KEYWORDS: Horizontal subsurface flow-constructed wetland, Purun tikus (Eleocharis dulcis), iron, acid mine drainage (AMD)