Factors related to adaptation status during and after school closure due to the outbreak of COVID-19 were investigated in children with neurodevelopmental disorders. A surveillance was conducted based on the medical records of a total of 134 students in the second, fourth, and sixth grades of elementary school. As a result, in the 2nd grade, there are many children with an intellectual level of 84 or less in a group of children spending the irregular life, in the 4th grade, adaptation after reopening of school was good in a group of children spending the regular life and difficult in a group of children spending the slightly irregular life. These results are considered to indicate the importance of regular lifestyle habits. Furthermore, 4th and 6th grade girls had difficulty adapting after resuming school, though many of them had a stable life during the school closure. Given these results it is speculated that the adolescent girls exposed stress by environmental changes and/or the autistic symptoms which became apparent due to the burden of social interaction. From the above, it was considered important to support people after puberty considering gender differences.