Objective: To predict the relationship between the toxicity and the structural parameters of chloro-Arenes drugs,a 3D-QSAR(three dimensional quantitative structure-activity relationship) model was established.Methods: By determining their lowest energy conformation,molecules are aligned according to one specific rule and the scope of the molecular field is defined around the aligned molecules.The characters of the molecule field such as the electrostatic field energy,steric field energy and also the field energy of hydrophobic region are calculated.Then Partial Least Square(PLS) method is exploited to analyze the relationship between the toxicity of compounds and characters of the molecular field and finally Comparative Molecular Similarity Indices Analysis(CoMSIA) model was built.Results:The cross-validated q2 of the model is 0.702 and the cross-validated r2 is 0.947,so the predictive abilities of this model is considerable.Conclusion:This model has a good predictive ability.To decrease the negative charge of substitutent in the para-position of methyl or decrease the hydrophilic property of substitutent in the para-position,meta-position and ortho-position of methyl can decrease the toxicity.