This paper presents micro self-reconfigurable modular robotic systems using shape memory alloy (SMA). The system is designed so that various shapes can be autonomously formed by a group of identical mechanical units. The unit realizes rotational motion by using an actuator mechanism composed of two SMA torsion coil springs. We have realized micro-size prototype units and examined their fundamental functions by experiments. An extended 3D system and its selfreconfiguration algorithm are also discussed. Key words: Modular Robotic System, Self-reconfiguration, Shape Memory Alloy Actuator, Micro-robot