Abstract: The liquid-liquid phase transfer catalysis suffers from two shortcomings: (1) The water molecules coextracted form a hydration shell, which retards the reaction and, sometimes, results in side reactions. (2) It seems to be not applicable for highly hydrophilic anions. For such reactions the solid-liquid phase transfer may be more suitable. But the factors affecting these reactions have not been reported as yet. This paper is the first effort in this area.From the data listed the following conclusions may be obtained:1. The solid-liquid phase transfer is a truely reversible reaction.2. In solvent with higher polarity and/or with higher hydrogen bonddonorability the equilibrium constant increases.3. Decrease of the electron density on the carboxylate group, either by electron withdrawing group or by intramolecular hydrogen bonding, favours the transfer of the carboxylate into solution. The intermolecular hydrogen bonding disfavours it.4. Transfer of salts of divalent anions is negligible or hardly detectable.