Structured illumination microscopy (SIM) has the axially sectioning capability due to the rejection of out-of-focus portion of image by patterned illumina-tion.To obtain a single sectioned slice of sample,three sub-images with a phase-shift of 2n/3 between two adjacent images are acquired.In this paper,anovel structured illumination microscope by using a digital micro-mirror device (DMD) for fringe projection is applied to capture structured illumination im-ages.