This study focuses on observing the brain function characteristics of maladaptive soldiers, through EEG analysis. The number of subjects was 1,119 including 59 maladaptive soldiers, 60 normal soldiers and 1,000 civil youths. The EEG measurements were performed from Sep. 2013 to Jan. 2014. As a result of the study, first, the soldier group's BRQ, ATQ, EQ, ASQ and BQ values were significantly higher than civil youth's, on the contrary to SRQ, ACQ, CQ which were higher in civil youth group. Second, compared to normal soldiers, the values of EQ and BQ were meaningfully low in maladaptive soldiers group, as well as the average values of each 8 quotient. In conclusion, military service can be assumed to have a positive effect on brain function of all soldiers due to regular life cycle, usual physical activities and balanced nutrition, but less effect on maladaptive soldiers who are exempted from those strict life.