Abstract: In order to further reduce the complexity of synthetic aperture interferometric radiometer imaging system, the circular and rotating array configurations have been proposed. However, these array configurations suffer the extremely complex brightness image reconstruction process. As the sampling data measured by these array configurations are distributed in a non uniform grid, the conventional cartesian FFT method could not be used directly. This paper presents an Non uniform Fast Fourier Transform(NUFFT) algorithm for imaging reconstruction of synthetic aperture radiometer. This algorithm relies on a combination of the fast Gaussian gridding algorithm and the use of FFT on an oversampled grid. The numerical simula tion results indicate that the proposed algorithm is accurate .