We have synthesized and investigated the physical properties of a new mixed valence iron complex, (n-C3H7)(4)N[(FeFeIII)-Fe-II(mto)(3)] (mto=C2O3S). This complex behaves as a ferrimagnet with T-N = 38 K and theta = -117 K From the analysis of the Mossbauer spectrum of (n-C3H7)(4)N[(FeFeIII)-Fe-II(mto)(3)] at 298 K, the spin state of Fe-II was determined to be the high spin state (S=2), but it was difficult to determine the spin state of Fe So that, in order to elucidate the spin state of Fe we have investigated ESR spectra, and confirmed the coexistence of high spin state (S=5/2) and low spin state (S=1/2) for the Fe-III sites. Moreover, we have synthesized (n-C4H9)(4)N[(FeFeIII)-Fe-II (mto)(3)]. This complex shows the ferrimagnetic phase transition at 41 K, and Weiss constant is -76 K, In our previous paper, we have reported that mixed-valence complex (n-C3H7)(4)N[(FeFeIII)-Fe-II(dto)(3)] (dto=C2O2S2) shows a new type of phase transition connected with charge transfer phase transition and spin-crossover transition around 120 K. In the title complexes, the charge transfer phase transition was not observed.