Effect of Ce filling fraction on the thermoelectric transport properties of p-ty pe Co-rich filled skutteudite compounds:CeyFe1.5Co2.5 Sb12 (y=0—0.46) were investigated. CeyFe1.5Co2.5Sb12 showed p-type conduction. Hall coefficient RH increased with increasing Ce filling fraction. Hole concentration p and electrical conductivity σ decreased with increasing Ce filling fraction. Se ebeck coefficient α increased with increasing Ce filling fraction. when Ce fill ing fraction was about 0.3, the lattice thermal conductivity κl reac hed the minimum value.It indicated that the effect of Ce rattling on phonon scat tering was the strongest as Sb-dodecahedron partial voids were filled by Ce. A m aximum ZT value of 1.1 was obtained for Co-rich Ce0.28Fe1.52Co2.48Sb12 at 750K.