The　Mn-II-based　porous　metal-organic　framework,　[Mn-3(btca)(2)(HCOO)((3)-OH)(H2O)(2)]2DMF　(1)　(H(2)btca　=　benzotriazole-5-carboxylate　acid),　was　prepared　by　the　solvothermal　reaction　of　Mn(CH3COO)(2)4H(2)O　and　H(2)btca,　which　was　characterized　by　infrared　spectroscopy,　thermogravimetric　analyses,　and　X-ray　crystallographic　study.　1　exhibits　3D　framework　with　1D　rectangle　channels　constructed　by　the　strip-shaped　chains　containing　[Mn-5((3)-OH)(2)(btca)(4)](-)　pentaclusters　subunits.　Furthermore,　the　magnetic　measures　show　that　1　exhibits　weak　ferromagnetic　behavior　at　low　temperature.