The local structure of the perovskite-type SrCo 1- xMn xO 3 solid-solution was investigated in order to study the effect of replacement of Co 4+ ions with Mn 4+ ions on the spin state of Co 4+ ion. The actual distances from Co 4+ or Mn 4+ ions to the first nearest-neighbors in the solid-solution, R[CoO] and R[MnO], are determined by EXAFS method. R[MnO] decreases with increase of Co 4+ ion content in the range 0.33 ≤ x ≤ 1.0 even though the lattice constant increases with Co 4+ ion content. On the other hand, R[CoO] increases with Mn 4+ ion content with a break at x = 0.33. A lever rule is well satisfied: (1- x) · R[CoO] + x · R[MnO] = R[(Co 1- xMn x)O], where R[(Co 1- xMn x)O] is the mean (Co,Mn)O distance by X-ray diffraction. These results indicate that the O 2- ion moves toward the Mn 4+ ion and away from the Co 4+ ion in the CoOMn combination. The strength of the ligand field for the Co 4+ ion becomes weak gradually with increase of Mn 4+ ion content because the O 2- ions around Co 4+ ions are more strongly attracted to Mn 4+ ions. Little change in R[MnO] in the range 0.0 ≤ x < 0.33 can be interpreted by forming little MnOMn combinations (i.e., the CoOMn and CoOCo combinations preferentially exist). It is proposed that the strength of the ligand field decreases sufficiently, when four of six CoO bonds in CoO 6 octahedra are lengthened at the composition of x = 0.33, so that the spin state of Co 4+ ion changes from low to high.