This study is to investigate whether pragmatic behavior of a child with ASD can be improved through the joint reading of parent-child picture books. The research subject is a 3-year-old with ASD. The independent variable is the parent-child picture book reading, and the dependent variable is the pragmatic behavior of a child with ASD during reading, such as behavior regulation and control, social interaction and joint attention. Three parent-child joint readings were conducted by reading three picture books -- "Dear Zoo.", "Little Goldfish Escaped." and "Did you see my cat." and of parent-child picture books can improve pragmatic behaviors of "behavior regulation and control", "social interaction" and " joint attention" for a child with ASD.