Two trinuclear cobalt complexes with the edge-sharing linear-type framework having benzylbis(2-pyridylmethyl)amine (bbpma), [{CoIII(bbpma)(μ-O2CCH3)(μ-OCH3)2}2CoII](X)2 (X=ClO4; [1](ClO4)2, X =PF6; [1](PF6)2), and one corresponding complex having ethylbis(2-pyridylmethyl)amine (ebpma), [{CoIII(ebpma)(μ-O2CCH3)(μ-OCH3)2}2CoII](PF6)2 ([2](PF6)2), were synthesized and the crystallographic and electronic structures were investigated. X-ray crystallography and magnetic measurements suggested that [1](PF6)2 and [2](PF6)2 were in the mixed-valent state and the mixed-spin state of Co(III)–Co(II)–Co(III) (LS-HS-LS), in which the electron spins were much localized on the central Co(II).