This paper introduces the development of an automated trainer that can conduct neuro-developmental treatment (NDT) rehabilitation for stroke patients. NDT training is a way to let patients have the feeling of walking with minimal intervention. During the training, therapists need to stabilize the patient's trunk and pelvis to stimulate the weight shift and pelvic rotation, and to assist limb control during the stance and swing phases to increase walking ability. Therefore, NDT rehabilitation is effective for stroke patients but labor-intensive for therapists. We have developed an automated NDT trainer that can mimic the therapists' intervention to reduce their workloads. First, we recruit subjects to conduct traditional NDT rehabilitation, where we apply a motion capture system to record the test subjects' motions and load cells to record the therapists' intervention force patterns during clinical NDT training. Second, we analyze the recorded data and develop an automated NDT trainer, which can detect the user's motions by the motion capture system and repeat the therapists' intervention by a closed-loop motor control system. Last, the designed trainer is applied to conduct NDT training for 10 stroke patients. The experimental results show that these test subjects' asymmetry of swing phases was improved after receiving the NDT training. In addition, the improvement by the trainer was greater than that by therapists, possibly because the trainer provides objective judgments and does not become fatigued. On the basis of the results, the developed trainer is deemed effective in providing suitable NDT training for stroke patients.