Based on QSPR of alcohol and ether organic compounds in water, geometrical optimization and electrostatic potential calculations were performed at the HF/6-31G* level for 73 alcohol and ether organic compounds. Linear relationships between infinite dilution activity coef- ficient (lnγ∞) of alcohols and ethers in water and theoretical descriptors of the molecular structure were established by multiple regression method. The result shows that the parameters derived from molecular electrostatic potential together with molecular surface area can be preferably used to express the quantitative structure-lnγ∞ relationship of alcohols and ethers in water. This reveals that this model has good predictive capabilities (RCV = 0.969). The molecular electrostatic potential has also been proved to have the general applicability in QSPR model of alcohol and ether organic compounds about γ∞ in water. The QSPR model established may provide a new powerful method for predicting γ∞ of organic compounds in aqueous systems.