After experiencing natural disasters, accidents, and shocking incidents, some children experience post-traumatic stress disorder (PTSD). A respiration control method that relaxes the body and mind may efficiently improve PTSD symptoms. Therefore, we developed a stuffed toy using two airbags to measure the respiration wave and guide a child’s respiration using the up-and-down movements of the toy’s abdomen to help them relax. The respiration wave was measured by the sensing device, and the child’s respiration could be led by the moving device. We then performed an evaluation experiment. Participants in the experiment consisted of nine healthy girls aged 8–10 years. The results showed that the respiration guidance resulted in fewer variations in the children’s mean heart rate than that with just hugging (p < 0.05). This result suggests that the respiration-guiding trial relaxes children compared with just hugging the stuffed toy without motion. The effectiveness of this stuffed toy in improving PTSD symptoms in children should be further evaluated.