Abstract: With the rapid socio-economic development in the plain river network area, river networks are strongly influenced by human activities, which degrades the physical habitat evidently. The Taihu Basin was taking as a case study. Six physical habitat indicators were selected to establish the evaluation system, including the weighted curvature, box dimension, actual integration of river network, regional river slope, river network density and river network complexity. Moreover, the Improved Entropy Weight and Matter Element Model was adopted to quantify the physical habitat of different catchments. The results show that: The quality levels of physical habitat vary mostly between “relatively good” to “bad”. The ranking order of habitat factors is: Box dimension>River network complexity>Regional river network weighted curvature > Actual integration of river network=River network density>Regional river network slope. The spatial variation of physical habitat in the Taihu Basin is obvious, while the quality of physical habitat of the western hilly area is better than that of the highly urbanized eastern plain area. Physical habitat evaluation on the river network scale is capable of representing the status quo of the basin directly, and effectively improves the performance of plain river network evaluation.