BaTiSi2O7　have　a　unique　TiO5　pyramid　polyhedron,　which　is　a　new　low　a　&　low　dielectric　loss　microwave　dielectric　material.　In　this　work,　the　BaTiSi2O7　powder　was　first　prepared　by　a　sol-gel　method.　The　formation　process　and　chemical　bond　of　the　samples　were　studied　by　XRD,　IR,　and　TEM.　X-ray　diffraction　reveals　that　Ba2TiSi2O8　is　first　formed　when　the　calcination　temperature　is　800　degrees　C;　when　it　reaches　1050　degrees　C,　Ba2TiSi2O8　begins　to　form　BaTiSi2O7　phase,　and　the　BaTiSi2O7　phase　content　is　increased　with　the　increasing　calcination　temperature.　The　optimum　condition　is　1175　degrees　C,　6　h.　The　IR　data　shows　the　changes　of　chemical　bond　when　the　BaTiSi2O7　is　formed.　TEM　photograph　shows　the　particles　present　irregular　morphology　with　an　average　size　of　400　similar　to　500　nm.　HRTEM　image　shows　that　the　interplanar　spacing　is　about　0.495　nm,　corresponding　well　to　the　(002)　plane