A novel ternary solid complex, Yb(C_5H_8NS_2)_3(C_ 12 H_8N_2), was obtained from treating hydrous ytterbium chloride, ammonium pyrrolidinedithiocarbamate (APDC) and 1, 10-phenanthroline (o-phen·H_2O) in absolute ethanol, and characterized by elemental analysis. The enthalpies of solution of hydrous ytterbium chloride, APDC, o-phen·H_2O, the mixture of APDC with o-phen·H_2O in absolute ethanol at 298.15 K, and the enthalpy changes of liquid-phase reaction of formation for Yb(C_5H_8NS_2)_3(C_ 12 H_8N_2) at different temperatures were measured by using a RD496-Ⅲ microcalorimeter. Fundamental parameters, the activation enthalpy (ΔHθ_≠), the activation entropy (ΔSθ_≠), the activation free energy (ΔGθ_≠), the apparent reaction rate constant (k), the apparent activation energy (E), the pre-exponential constant (A) and the reaction order (n), were obtained by the combination of the thermochemical data of the reaction and kinetic equations with the data of thermokinetic experiments. The enthalpy change of complex formation from the reaction of the regents in solid phase, Δ_rHθ_≠(s), was calculated on the basis of an appropriate thermochemical cycle and other auxiliary thermodynamic data. Based on a RD496-Ⅲ heat conduction microcalorimeter, a calculation model for determining the specific heat capacity of solid substance was developed, and the title complex, c_m, were accordingly determined. A novel ternary solid complex, Yb (C_5H_8NS_2) _3 (C_12H_8N_2), was obtained from treating hydrous ytterbium chloride, ammonium pyrrolidinedithiocarbamate (APDC) and 1,10- phenanthroline (o-phen · H_2O) in absolute ethanol, and by elemental analysis. The enthalpies of solution of hydrous ytterbium chloride, APDC, o-phen · H 2 O, the mixture of APDC with o-phen · H 2 O in absolute ethanol at 298.15 K, and the enthalpy changes of liquid-phase reaction of formation for Yb (C_5H_8NS_2) _3 (C_12H_8N_2) at different temperatures were measured by using a RD496-Ⅲ microcalorimeter. Fundamental parameters, the activation enthalpy (ΔHθ_ ≠), the activation entropy (ΔSθ_ ≠), the activation free energy (ΔGθ_ ≠), the apparent reaction rate constant (k), the apparent activation energy (E), the pre-exponential constant (A) and the reaction order (n), were obtained by the combination of the thermochemical data of the reaction and kinetic equations with the data of thermokinetic experim ents. The enthalpy change of complex formation from the reaction of the regents in solid phase, Δ_rHθ_ ≠ (s), was calculated on the basis of an appropriate thermochemical cycle and other auxiliary thermodynamic data. Based on a RD496-III heat conduction microcalorimeter, a calculation model for determining the specific heat capacity of solid substance was developed, and the title complex, c_m, were learned determined.