This paper introduces the mechanical structure and control technique of the robot fingers. The fingers has been developed as elemnts of the robot hand which has 20 joints and 16 degrees of freedom in order to express fingerspelling. The joints are driven by the small DC servomotors and the shape memory alloys (SMA), The hand system will consist of four parts of "hand mechanism", "drive device", "control unit" and "man machine interface". As the first step of the research, this paper introduces especially about the control technique related to the second axes of the fingers driven by SMA. Basically, the finger can be bended and unbend by a pair of SMA wires. Furthermore, to realize those smooth motions, the control system is designed based on an experimental result of system identification. Finally, we report the simulation and experimental control results.