Abstarct: There are various approaches for depth estimation of anomalous potential field data. Spectral analysis of gravity and magnetic data has been used extensively for many years to derive the depth to certain geological structures, such as the magnetic baxsement or the Curie temperature isotherm. The estimation of the depth of anomalous sources is usually carried out by Spector and Grant method. In this method geophysical source parameters such as density, susceptibility sequences etc. have been assumed as uncorrelated and randomly distributed. Assumption of the uncorrelated random sources is not true as revealed from many borehole data in the German continental deep drilling project (KTB) around the globe. Therefore the generalized spectral method for gravity and magnetic data, baxsed on the realistic distribution of anomalous sources, is found useful for finding the depth values and statistical properties of the source distribution. The interpretation of the gravity and magnetic data is preferred in frequency domain because of simple relation between various source models and field. If the logarithm of obtained power spectrum of potential field data that transformed in Fourier domain, plot versus wave number values, although some factors affect the plot, but the depth is dominant factor. The depth to various source is thus found from the slope of this plot. In present research work, the efficiency of generalized power spectrum has been investigated using theoretical model of gravity and magnetic and the results have been compared with commonly power spectrum. At the end, the generalized power spectrum method has been performed in order to the depth estimation of anomalous sources of two case study, baxsed on magnetic data of Oshvand-Nahavand area and gravity and magnetic data of sedimentary basin of Moghan at the northwest of Iran, respectively. baxsed on the previous studies conducted in the area, our estimation of the depth of anomalous sources by means of power spectrum approach has been evaluated and confirmed.