A technique called surface plasmon resonance digital holographic microscopy (SPRDHM) for optical imaging of cell membranes is proposed. The intensity and phase distributions of the reflected light that is modulated by the cell membrane in surface plasmon resonance can be simultaneously obtained. The imaging principle and capability are theoretically analyzed and demonstrated by experiments. In addition, the technique is compared with total internal reflection digital holographic microscopy (TIRDHM) in theory and experiment, respectively. The results show that the SPRDHM technique is better in spatial resolution and phase sensitivity than the TIRDHM technique for imaging of cell membranes.