This study assessed the quality of life of 89 children with Neurodevelopmental Disorders, as well as their parents, grandmother and even adult sister at Shimada Ryoiku Hachioji Center in Tokyo, Japan, in May 2020 and May 2021 during the COVID-19 pandemic and also explored the possible factors affecting their quality of life. These were changes in the children's lifestyles such as increased exercise, poor school attendance, increased gaming and internet time, and acute obesity; as for the parents, they felt a greater burden regarding living expenses, and low social welfare income. In which it was found that, the family economic situation and a state of depression of parents can have a negative or positive impact on the quality of life for themselves and their children; moreover, the parents' severe depressive state was associated with greater parental stress and, therefore, increases the most severe parental depressive state.