A novel full-field optical coherence tomography (FFOCT) system with low cost and high resolution is developed for imaging of cells and tissues. Different from other FFOCT systems illuminated with optical fiber bundle, the improved Khler illumination arrangement with a halogen lamp is used in the proposed FFOCT system. High numerical aperture microscopic objectives are used for imaging and a piezoelectric ceramic transducer (PZT) is used for phase-shifting. En-face tomographic images can be obtained by applying the five-step phase-shifting algorithm to a series of interferometric images which are recorded by a smart charge coupled device (CCD) camera. Three-dimensional images can be generated from these tomographic images. Imaging of the chip of Intel Pentium 4 processor demonstrats the ultrahigh resolution of the system (lateral resolution 0.8 μm), approaching the theoretical resolution 0.7 μm×0.5 μm (lateral×axial). En-face images of cells of onion surface and potted plant leaves cells show the excellent performance of the system for generating en-face images of biological tissues. The system is characterized by its high resolution, low cost and simple arrangement for adjustment, providing a practical method of performing FFOCT imaging.