A　two-dimensional　apodized　grating　coupler　for　interfacing　between　single-mode　fiber　and　photonic　circuit　is　demonstrated　in　order　to　bridge　the　mode　gap　between　the　grating　coupler　and　optical　fiber.　The　grating　grooves　of　the　grating　couplers　are　realized　by　columns　of　fully　etched　nanostructures,　which　are　utilized　to　digitally　tailor　the　effective　refractive　index　of　each　groove　in　order　to　obtain　the　Gaussian-like　output　diffractive　mode　and　then　enhance　the　coupling　efficiency.　Compared　with　that　of　the　uniform　grating　coupler,　the　coupling　efficiency　of　the　apodized　grating　coupler　is　increased　by　4.3%　and　5.7%,　respectively,　for　the　nanoholes　and　nanorectangles　as　refractive　index　tunes　layer.