Aim and Background: Inability in cognitive processing, emotional awareness, and emotion regulation is called Alexithymia. The alexithymia is a common problem among people. The purpose of this study was to determine the effect of emotional regulation instruction on alexithymia of high school students. Methods and Materials: The research method was a semi-experimental design with pre-test and post-test with control group. The statistical population of this study included all female secondary high school students of Neyshabur who studying in the academic year of 2017-18. Among 20 high school students, 30 subjects were selected clustered sampling method and assigned in two control group (n=15) and experimental group randomly (n=15). The intervention program was conducted in 8 sessions of 90 minutes, weekly for the experimental group and the control group received was in wait list. Data were analyzed using covariance analysis Findings: The findings of the study showed that emotional regulation training reduced alexithymia (p<.001). Conclusions: To explain the above results, it can be said that are affected by the emotional ordering of individuals, so that the training of emotional regulation skills reduces alexithymia.