Children who are undergoing hospital treatment often have problems interacting with the surrounding environment. This condition for a child becomes a state of crisis that occurs because the child is trying to adapt to the environment in the hospital, so that the condition raises anxiety for the child both against their own children and family. The purpose of this study was to determine differences in the anxiety level of school-aged children before and after obtaining information about injection administration in the control group and intervention group. This research method used quasi experiment design with sample of 17 respondent of control group and 17 respondent of intervention group. Sampling using purposive sampling technique. Data collection uses an observation sheet on child anxiety. Data analysis using difference test 2 mean. The results obtained There are differences in anxiety after being given intervention in both groups in hospitals Ambarawa with p value of 0.010. Suggestions to local health officials to continuously provide counseling and correct information about drug delivery. So as to reduce the anxiety of school-age children when receiving an injection treatment.