A phosphorus flame retardant named resorcinol bis(cyclic 2,2-dimethyl-1,3-propanediol phosphate) (RCDMPP) was synthesized and characterized by high-performance liquid chromatography (HPLC), elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR), mass spectra (MS), and nuclear magnetic resonance (NMR). Its thermal stability was evaluated via thermogravimetric analysis (TGA), and the fusion enthalpy and melting point of RCDMPP were detected by differential scanning calorimetry (DSC). The solubilities of RCDMPP in selected solvents at T = 293.15 to 333.15 K and atmospheric pressure were measured via a static-analytic method. The solubility data were correlated with modified Apelblat, Scatchard-Hildebrand, Buchowski-Ksiazczak (lambda h), nonrandom two liquid (NRTL), Wilson, and universal quasichemical (UNIQUAC) equations. The calculated results obtained from these models showed good agreement with the experimental data, and the NRTL, Wilson, and UNIQUAC models give better correlation results compared with modified Apelblat and lambda h models. The solubility parameter of RCDMPP was calculated by use of the Scatchard-Hildebrand methodology.