The coil sensitivity distribution is one of the most essential elements of any parallel imaging methods, which provides the spatial information for unfolding the aliased images due to under sampling. In general, there are two basic calibration methods to obtain the coil information: pre-scan and autocalibration. In this paper, the standard and advanced calibrating methods for coil sensitivity estimation are firstly reviewed. Secondly, in vivo applications of the up-to date methods are accomplished. Finally, the problems of these calibration methods are post. At last, the paper has outlined the practical considerations of the calibration techniques.