A hybrid method, a combination of Modal summation, Finite Difference and Green Function, is used to generate synthetic signals. In this procedure we try to synthetically generate a small event using the hybrid of MS and FD as green function to simulate target event through GF method. This is tested using an aftershock recorded following the Bam earthquake. The result of synthetic signals by this method and observed records of Bam are compared both in time and frequency domains and shows good agreement. This method is presented for the areas with no remarkable observed record where the simulation could help to cover the lack of data.