The purpose of this study was to provide the twin brothers with ADHD an appropriate intervention based on the outcomes of functional assessment. The major findings were as follows: 1.Through the functional assessment, these findings showed that the symptoms of ADHD itself caused verbally disruptive behavior, but the two clients tended to have more verbally disruptive behavior when being bored, being neglected by their teacher or having a to-be-dealt mood from the previous session or during recess in order to obtain the teacher＇s attention or to vent their emotions. 2.After two strategies being intervened, the problem behaviors of both cases had reduced effectively, yet, it did not show constant tendency toward promising improvement. 3.The intervention named as packaged strategy showed different outcomes of improvement between the two clients. For case II, the intervention of packaged strategy had a better result than that of single strategy. As for case I, there was no significant difference between the two strategies. As contrasted with qualitative data, the results indicated that the brothers with ADHD were twins and studying in the same class, but the individual difference still existed.