Earthworm plays a key role in the terrestrial ecosystem and is often used as test organism in chemical risk assessment. To understand how earthworm accumulates hydrophobic organic chemicals (HOCs) and models for its prediction are very important to security of the food chain and chemicals management. A brief introduction is presented to processes of earthworm accumulation of HOCs and its affecting factors, and several models, as well, for prediction of the accumulation, such as empirical model, rate model, equilibrium-partition model, mechanical model and fugacity model. In general, earthworm accumulation of HOCs has two pathways: ingestion and percutaneous absorption through simple diffusion. As for most of the HOCs the latter is the dominant one. However, the contribution of ingestion increases with the increasing hydrophobicity of the chemicals (logK_ow>5), especially in soils high in organic matter content. All the prediction models, except the rate model are developed on the basis of the three hypotheses: (1) HOCs are mainly persistent organic pollutants and their basic behavior in the soil-earthworm ecosystem is the process of distribution and equilibrium between the solid-liquid phase of the soil and the biophase of earthworm; (2) the fat phase of earthworm is the main accumulation pool of such organic pollutants; and (3) HOCs inside earthworm are not subject to any or negligible biotransformation or metabolism. At the end, the paper suggests that the research in the future should focus on behaviors of HOCs inside earthworm, such as distribution, so as to understand more about eco-toxicology of HOCs in earthworm.