Temperature dependence of Fe-57 Mossbauer spectra for TBA[Fe(tdas)(2)] is measured to obtain the information on the spin state and the phase transitions. The large quadrupole splitting due to the S = 3/2 spin state increases reenteringly in the intermediate temperature region (190 - 230 K on cooling and 200 - 240 K on heating). The small increase in the quadrupole splitting and the continuous decrease in the isomer shift suggests the 3/2 spin state does not change, supporting the interpretation of the magnetic susceptibility.