This study aimed to investigate the defense style among the students of tenth and eleventh grades in South Batinah Governorate. The total sample of the study was (765) male and female students. To get data from the sample group, a questionnaire of defense style (Thagaisin 2005) was conducted. Results of the study showed that the widespread defense style were altrisum, self assertion, self-observation, idealization and anticipation. On the contrary, the defense style of passive aggression, projection, devaluation self were the least frequent occured. The study also showed statistical differences in the style of altrusim, suppression, omnipotence in favor of females and passive aggression in favor of males related to the variable of sex. Similarly, statistical differences were explored in the style of passive aggression, supperssion, rationalization, projection, self-observation, devaluation self, projective identification and anticipation attributed to the variable of studying achievement. However, no differences occured in the remaining style. Also, the study found that the differences in the style of suppression, rationalization and self-observation were more examined in outstanding students while the differencez in the style of passive aggression, projection, omnipotence and devaluation were more explored in weak students.