Spectrum compatibility is commonly used as a tool for ground motion record selection in order to perform dynamic analysis. Conditional mean spectrum calculation, which can be used as a target spectrum, requires obtaining correlation coefficients between spectral acceleration values at multiple periods. To date, the correlation coefficients have not been evaluated exclusively from ground motions recorded in Iran. This study represents results obtained from the calculation of correlations for spectral acceleration values from Iranian ground motion data and Zagros and Alborz-central Iran seismic regions, separately. The obtained results can be used for conditional mean spectrum calculations at Iranian sites. The observed correlation coefficients for Iranian records are compared to the correlations developed from the Western United States ground motion data. It is seen that correlation coefficients obtained from the Western United States ground motion data are less than the ones calculated in the study and therefore would cause further reducing of the target spectrum of interest.