The study aimed at identifying knowledge of parents of children with autism spectrum disorder of behavior modification methods and their training needs accordingly. The sample of the study consisted of (98) parents in Jordan. A scale of behavior modification methods was constructed, and then validated. The results of the study showed that the knowledge of the parents of children with autism spectrum disorder was medium. The highest percent was for satiation style, and the least for generalization style. The study also revealed that parents need to be trained in six methods of behavior modification. The most important need was for generalization style then the effectiveness of reinforcement. Study finally revealed that there are significant differences in parents' knowledge of behavior modification due to parent's gender in favor of mothers but there were no significant differences due to parents' education, child's gender, and child's age.