Biomechanics of the cell has been gathering much attention because it affects the pathological status in atherosclerosis and cancer. In the present study, an ultrasound and optical combined microscope system for characterization of a single cell with multiple ultrasound parameters was developed. The central frequency of the transducer was 375 MHz and the scan area was 80 × 80 micron with up to 200 × 200 sampling points. An inversed optical microscope was installed in the system and simultaneous observation of the cells cultured in the petri-dish was available. Two-dimensional mapping of the multiple ultrasound parameters such as attenuation, sound speed and acoustic impedance as well as the thickness and density of the cell was realized by the system. Sound speed and thickness of 3T3-L1 fibroblast cell were successfully obtained by the system. The ultrasound and optical combined microscope system may contribute to understand the cellular biomechanics.