Abstract: Monitoring and post-assessment play an important role in assessing construction effect and guiding subsequent construction of eco-clean small watershed. However, there are few related studies on the monitoring and post-assessment of eco-clean small watershed. Based on construction targets of eco-clean small watershed, the representative monitoring factors were selected to assess the construction effect and the monitoring methods are briefly described. According to the nature-society-economy characteristics of eco-clean small watershed, 10 indexes from the perspectives of human society and natural environment were selected to establish the post-assessment index system, and the assessment methods and criterion were proposed. The study can provide a basis for assessment of eco-clean small watershed construction.