Abstract: Linear solvation energy relationships are of a great value in investigating quantitative structure-retention relationship and quantitative structure-activity relationship, and predicting chromatographic retention indices of drugs. Several quantitative relationships in different in vitro biomembrane-mimetic models between retention factors and molecular descriptors have been established successfully and used to clarify drug-membrane interaction mechanisms. Quantitative structure-activity relationships also have been established to predict drug intestinal absorption, permeation of skin and blood-brain barrier. This review focused on the significance and widely application of linear solvation energy relationships in quantitative assessment for mechanisms of partitioning and absorption of drugs. The discrepancy and limits of linear solvation energy relationships were also discussed, which gives us a better insight into investigation of partitioning and absorption of drugs.