Group contribution models such as ASOG or UNIFAC were known to be inaccurate in the prediction of infinite dilution activity coefficients (gamma(infinity)) for most of the systems containing water. To overcome the weakness inherent with the UNIFAC models, Zhang et al. (Fluid Phase Equil. 149 (1998) 27) have recently proposed a group-contribution-based model with mixture-type groups, where the mixture-type group is a hypothetical concept for taking into account the particular hydrophobic effects in aqueous organic systems. The proposed methodology has been proven to be applicable to alkane/water and alcohol/water mixtures in our previous study. In this work, the proposed method was further extended to the other classes of compounds, e.g. aromatics, ketones, acids, aldehydes, esters, ethers, nitriles and halogenated compounds. Compared to the conventional UNIFAC models, the proposed method demonstrates significant improvements in accuracy for various organic compounds in water mixtures.