Abstract：This study pointed out that most previous studies dealing with physical activity and sleep quality of children with autism spectrum disorder (ASD) were used questionnaires as research tool. The physiological wearable device is more objective and accurate to measure the amount of physical activity and sleep quality. The purpose of this study was to assess the physical activity and sleep quality of children with ASD and typically developing children by using physiological wearable device. Participants who met the requirements of this research program were recruited through autism-related associations or organizations in north, central, and south areas of Taiwan. Fifty children with ASD (age: 11.2 ± 3.0 years; 44 males, 6 females) and 50 typically developing children (age: 11.6 ± 2.4 years; 40 males, 10 females) were participated in this study. The Xiaomi Bracelet 2 was used to measure the physical activity and sleep quality of participants for 1 month. The results showed that the daily steps of children with ASD were significantly less than that of children without ASD. In addition, the sleeping duration in children with ASD was significantly less than that in children without ASD. We concluded that the physical activity and sleep quality in children with ASD are inferior to children without ASD. This study also suggested that the physical activity and sleep quality in children with ASD should be improved by related caregivers. (Full text)