This paper presents a small-size self-reconfigurable modular machine using shape memory alloy (SMA). The system is designed so that various shapes can be actively formed by a group of identical mechanical units. Each mechanical unit realizes two-dimensional rotational motion by using a novel actuator mechanism composed of two SMA torsion springs which can generate sufficient motion range and torque. The size and the weight of a unit are approximately 5[cm] cube and 80[g]. The reconfiguration motion of the machine is verified by many-unit experiments. Applicability of the developed unit model to a 3-D self-reconfigurable system is also discussed.