AbstractThis study focused on the aggressive behavior of child in elementary school, and efforts to cope the aggressive behavior. This research used the emotion regulation training that aims to determine about the influence of emotion regulation training against aggressive behavior in school’s child. The hypothesis in this study was emotion regulation training influential to reduce aggressive behavior of child in fifth grade and ten years old. This research used a Single Case Experimental Design by “A-B with singletarget measure and follow-up” models. Research subjects were two elementary school students, aged 10 years, who had aggressive behavior. Training of emotion regulation was done over the fiveconsecutive sessions, and observed aggressive behavior during the six days before training (phaseA), six days after training (phase B) and four days at follow-up. Observation results were analyzed with a visual inspection technique using a graph, and showed there is reduction in aggressive behavior’s subject at phase B after emotion regulation training. The results obtained showed that emotionregulation training can reduce aggressive behavior for child in elementary school according to the criteria of the subject.Keywords: emotion regulation training, aggressive behavior of school’s child.