We present a new method to reconstruct high resolution SAR images. When the far-field data arranged in the polar format, a 2-D Fourier transform can achieve the image reconstruction. But the data do not fall on a Cartesian grid, we introduce 2-D Nonuniform Fast Fourier Transform (NUFFT) to reconstruct the SAR image directly. It is the first time to use NUFFT technology in SAR image reconstruction. Instead of interpolating the input data, NUFFT interpolate the exponential function for each sampling point. The technology could easily extended to high dimensional by tensor product. The 2-D NUFFT is very suitable to reconstruct SAR image. A ground target example will shown to demonstrate that the reconstructed images have higher resolution than the general method when using the same data.