Abstract: Since the recordation of digital holograms limited by the resolution of CCD,the obtained holograms are undersampled.The cause of this problem are analyzed and the method of recordation and utilization of the undersampled holograms is presented.With this method adopted in the experimental data processing of microscopy digital holography,a relatively perfect phase of onionskin cell could be obtained.And it proved that the method was effective.Compared with the results got from unrestored holograms,the method of recordation expanded the applicable size of undersampled holograms.Since the problem of the undersampled holograms exists universality in digital holography,the method is of some practicality.