It is indicated that the serious difficulty will be encountered in order to obtain a short wave-length laser by the tradition technique, and new light source is seeked. Besides the channeling radiation, there is an undulator radiation in acoustically bent crystal. The undulator radiation is panalle to the beam at a maximum/minimum for the undulator obital, the case is simular to free electron lasers (FEL). An emied photon at successivelly a maximum/minimum of the undulator obital is stimulated, and radiation frequency is higher than FEL. The frequency and the spectral distribution of the channeling radiation and the undulator radiation are described in a harmonic approximation, the relationship between them is discussed. The possibilities of using the crystallographica undulator radiation as X-laser and γ-laser are analysed detailly.