Abstarct: In this study using spectral analysis of aeromagnetic data can provide important information about temperature distribution in depth. The methods used to estimate CPD in different parts of the world, mostly consider the crustal rocks magnetization as a random function of the position (x, y) while the crustal rocks magnetization shows a fractal behavior. In this study, we used both models and presented the results. For this purpose the reduced-to-pole aeromagnetic data were divided into 55 overlapping windows of the size of 80 × 80〖km〗^2 (overlapped 50 with the adjacent window). The 2D power spectrum of aeromagnetic data for each window was computed with fast Furrier transform (FFT) method by Oasis montaj software. Then use these values as inputs, a MATLAB programme was written to produce the radial power spectrum and by plotting a graph of the logarithm of Power against Frequency (radians per km) the CPDs were obtained for each block. Therefor the top and bottom to the depth of magnetic sources estimate and bottom to the depth of magnetic sources assume as a Curie point depth. By the spectral analysis, was estimated CPDs using, the centroid method, forward modelling spectral peak method and de fractal method for the study area varies from 9.2 to 13.9 km, 8.9 to 13.7 km and 7.2 to 12.9 km respectively. Also calculated the fractal parameter between values 1 to 2. Then by mapping the Curie point depth, thermal gradient and heat flow of study are we concluded that the all of study area has potential for more geothermal exploration. At the between methods of investigate, the minimum value of CPD obtains with Using the de-fractal method. The results of the Curie depth estimation and the available heat flow data indicate that the two regions in the northwest of Iran, is promising area for geothermal exploration particularly at Sabalan geothermal area.