The chemical shift and the equilibrium concentration of water have been determined as a function of water activity at 25°C in the three solvents di-isopropyl ether, dibutyl phthalate and chloroform. Using the computer program LETAGROP various equilibrium models are tested (cf. Table 2). The models giving the best fit are given in Table 3. While a monomer-dimer equilibrium fit the data in di-isopropyl ether and dibutyl phthalate, chloroform is best fitted with a monomer-trimer equilibrium. With the aid of the chemical shifts evaluated and of a very simple model it is found that for the solvents nitrobenzene, dichloro-ethane, di-isopropyl ether, linear and/or cyclic polymers explain the chemical shifts equally well. In chloroform a cyclic trimer fits the data better than a linear trimer. The data for dibutyl phthalate indicate strong interactions between the water dimer and the two ester groups of the solvent molecule.