Stream network structure in Xunhe watershed is simulated using GIS methods for the buffering area construction. NDVI in 1997 and 2004 is calculated to examine its relationship with stream order. Results indicate that stream network in mountain area can be well simulated,stream order and NDVI are closely re-lated,and the NDVI in 2004 is higher than in 1997. These suggest that the eco-environment in Xunbe water-shed has been improvement in recent years.