Abstract:The study was conducted in farmland with low productivity in Huantai County, Shandong Province of China North Plain to study the impact of organic manure and chemical fertilizer application on earthworm population. The result shows that there are 3 families, 6 genera and 7 species. Drawida gisti is the dominant species. The seasonal variation of the earthworm population density has following trend: August> September>April >May>November. The chemical fertilizer increased the earthworm population compared wit...