The strong backscattering homogeneous region, i.e., a uniform region with a high and constant backscattering coefficient, is important for synthetic aperture radar (SAR) image quality assessment and SAR radiometric calibration, which, however, is difficult to realize in practice with a known backscattering coefficient. We realize a strong backscattering homogeneous region with a known backscattering coefficient in SAR images by utilizing designed metal grids. First, we propose a manmade grid-structure target and realize it with aluminum in practice, which is named the metal grid. Then, the backscattering coefficient of the designed metal grid is simulated in the computer simulation technology (CST) microwave studio and measured by a radar cross-section (RCS) measurement instrument in a microwave anechoic chamber. Both CST simulation results and RCS measurement results confirm the strong backscattering property of the designed target. In addition, by utilizing the designed target, we realize a test field consisting of several strong backscattering homogeneous regions with different sizes at Shanghai Jiao Tong University, Shanghai, China. The spaceborne experiments have been carried out by the TerraSAR-X sensor over the test field in two flight campaigns in X-band with VV polarization. Experimental results demonstrate the strong backscattering property and homogeneity of the realized regions.