The transformation from electromagnetically induced transparency to amplification without inversion based on spontaneously generated coherence was studied by proposing a lambda type three-level system. Three transparency windows are observed when two ground state hyperfine levels are driven by a microwave field. The transparency shifts into amplification by using the coupling of electromagnetically induced transparency and spontaneously generated coherence with appropriate angle. The results show that there is no population inversion between the ground state and the excited state level and no population inversion between two ground state hyperfine levels when amplification is observed, but the system must go through population inversion of two ground state levels in the process of generating amplification. The populations of two ground state levels can be controlled though the adjustment of the frequency detuning of the microwave field to facilitate the generation of amplification.