Smart Phones Usage and It's Relationship with Social Adjustment Among Female High School Students at Alkhobar Governate in Kingdom of Saudi Arabia Abstract: This study Aimed to find out the relationship between smart phones usage and Social Adjustment among female high school students at Al Khobar Governate in Kingdom of Saudi Arabia by study year 2012-2013. The researcher followed the descriptive; survey, correlation and comparative research method, and choose a cluster random study sample consisted 370 smart phone users, which ratio represent the four regions of Kokobar, and the three grades of high school. For the purpose of collecting data; she developed and applied a survey questionnaire to discover students' smart phones usages and daily time average frequency of use as a main variables of smart phone usage, and Social Adjustment Scale to discover students' social adjustment, and made sure that it was valid and reliable to study population by applying it on primary sample had taken out from it. Results showed that all students having a moderate and equally using of smart phone in voice call and SMS, internet search and entertainments, but almost all of them use social communicating sites, about half of them daily frequently using it for (6) hours and above, and their social adjustment levels were moderate to high levels, and it didn't show any serious problems in social adjustment among study sample, but with a need of developing social skills for some of students. Results also showed a limited but significant positive relationship between using smart phones in voice calling and SMS, internet search and entertainments and the students' social adjustment, but it was not significant in determining student's level of social adjustment, and it also showed a weak but significant negative association at (0,01) significant level- between an average of student's daily time use of smart phone and her social adjustment. Results also indicate statistically significant differences in the degree of students' social adjustment due to their use of voice calling and SMS in favor of using, and due to student's time average of daily using of smart phone in favor of using it for one to two hours per day.