Two　compounds　with　3-methylbenzoic　acid　(HL)　[Co(L)(2)(4,4＇-bipy)(n)　1　and　[Zn-2(L)(4)(4,4＇-bipy)(n)　2　(L　=　3-methylbenzoic　acid)　have　been　hydrothermally　synthesized　directly　and　characterized　by　single-crystal　X-ray　diffraction　analysis,　elemental　analyses,　IR　spectra　and　ultraviolet-visible　diffuse　reflection　integral　spectra　(UV-Vis　DRIS).　The　two　compounds　are　both　one-dimensional　infinite　chains.　The　structural　difference　is　that　1　is　a　double-chain　structure　and　2　is　only　a　single　chain　one.　At　the　same　time,　the　carboxylate　groups　adopt　different　modes　in　the　two　compounds,　relatively.　Additionally,　in　order　to　explore　the　structural　characteristic,　two-dimensional　IR　spectra　are　investigated　for　1　and　2.　Photo-luminescent　property　of　2　is　also　researched　in　detail.