Abstract: As a critical component of soil ecosystem, earthworm can improve soil structure and relates closely to soil nutrient cycling, playing an important role in promoting soil quality and productivity. However, there is lack of systematic study on the field sampling methods for earthworm, especially in China. This paper reviewed the operational processes of commonly used field sampling methods for earthworm, and discussed their corresponding merits, efficacy, and potential influence on research results. To achieve a complete and accurate characterization of earthworm community size and structure, the method of chemical repellent combined with handsorting could work well at the sites where physical disturbance was acceptable, while the AITC (allyl isothiocyanate) method would be a favorable option at the sites where soil destruction was not feasible.

Key words: hand-sorting, chemical repellent method, electrical octet method, earthworm, sampling method, Eupolyphaga frass, extract, root-knot nematode, volatile, chitosan.