This study develops a lens-free microscope system and an algorithm to realize microscopic imaging with a relatively large field of view and high resolution. The proposed system consists of an LED light source, a pinhole, a sample holder, and a CMOS imager. The system parameters, such as the pinhole diameter, size of the imager, distance between the LED and sample, and distance between the sample and imager were studied and optimized. Furthermore, an angular spectrum method was developed for recovering sample images from holograms captured by the CMOS imager.Finally, the developed system was employed to demonstrate lens-free microscopic imaging of a micropatterned testing chip with a standard resolution in addition to that of lung cancer cells in suspension.The developed holographic lens-free microscopic system has a resolution of 4.4 μm and an imaging field of view up to 5.7 mm×4.3 mm; furthermore, it is capable of imaging the micropatterns in the test chip as well as individual lung cancer cells.Thus, the proposed holographic lens-free microscopic system demonstrated microscopic imaging with a relatively large field of view and high resolution; moreover, it exhibited the advantages of a simple structure and the avoidance of aberration interference.