SiO2　micro-cantilever　has　been　widely　used　in　the　field　of　chemical　and　biological　sensors　due　to　its　high　sensitivity.　In　order　to　further　improve　the　dynamic　sensitivity　of　SiO2　micro-cantilevers,　the　fabrication　and　its　sensor　application　based　on　higher　resonance　modes　are　studied　in　this　work.　First,　Silicon-on-insulator　(SOI)　is　used　as　starting　material　for　the　fabrication　of　T-shaped　SiO2　micro-cantilevers　with　different　lengths.　Then,　commercial　atom　force　microscopy　(AFM)　with　accurate　photoelectronic　system　is　employed　for　the　characterization　of　the　frequency　and　the　frequency　shift　before　and　after　mass　adsorption.It　is　found　that　the　first　three　bending　frequencies　of　the　T-shaped　SiO2　micro-cantilevers　with　total　length　of　250　μm　are　18.86　kHz,　164.27　kHz　and　467.25　kHz,　respectively,　which　are　well　consistent　with　the　simulated　values.　Moreover,　for　the　same　amount　of　mass　change,　the　higher　the　flexural　resonance　mode　is,　the　larger　the　frequency　shift　of　the　micro-cantilever　will　be,　showing　an　increasing　sensitivity.　The　frequency　measurement　of　gold　deposition　reveals　that　the　sensitivities　of　the　first　three　modes　are　1.36　Hz/pg,　9.78　Hz/pg　and　26.92　Hz/pg,　respectively.　Immunological　reactions　are　also　conducted.It　is　found　that　at　the　second　harmonic,　a　21.5　pg　mass　absorption　can　be　detected.