Improving the quality of family life (FQoL) is one of the ultimate goals for autism spectrum disorder (ASD) intervention, and parenting self-efficacy and social support are critical for the well-being of families. However, longitudinal studies focusing on FQoL and its predictors for families of children with ASD are scarce. This study aims to describe the characteristics of FQoL among parents of children newly diagnosed with ASD at two waves (newly diagnosed and diagnosed after one year) and to explore the predictors of FQoL at two waves. It was conducted at a tertiary hospital in Guangzhou, China. A total of 156 parents and their children were included in Wave 1, followed up with 110 in Wave 2 after 1 year. The overall satisfaction of FQoL improved (t = -2.128, p < 0.05), while satisfaction with physical/material well-being decreased (t = 5.972, p < 0.01). Additionally, the overall importance rating of FQoL improved but did not have statistical significance (p > 0.05). Parents with higher parenting self-efficacy (beta = 0.716, P < 0.01), and more subjective social support (beta = 1.127, p < 0.001) reported higher satisfaction with FQoL, and those with better social support utilization (beta = 1.066, p < 0.05) reported higher importance for FQoL. FQoL needs to be improved in the early stage of ASD diagnosis, and parental self-efficacy and social support can serve as the intervention targets.
