Muscle cell actuators are composed of skeletal muscle cells and collagen intercellular matrix. Muscle cells adhere to collagen fibers and contraction along with the direction of collagen fiber. Collagen fibers in a muscle cell actuator transmit contraction force of each muscle cells along longitudinal direction. In order to improve contraction force of muscle cell actuators, it is very important to align collagen fibers. In this study, we aim to achieve alignment of collagen fibers in the actuator. We developed the automatic culture system which apply cyclic stretch to muscle cell actuators. We estimated the structure the actuator by using a scanning electron microscope and fluorescent observation. And we confirmed that cyclic stretch induced alignment of collagen fibers in the muscle cell actuators.