The research aims to verify the factorial structure, as well as measure the level of smartphone addiction among university students, and to detect differential item functioning according to gender variable (male-female) and study language variable (foreign language - Arabic language) for "smartphone addiction" scale (Kwon, Lee, et al., 2013) Using the Rasch model, and to identify the differences,mean between the students on the smartphone addiction scale and its different dimensions depending on gender variable (male-female) and variable of study language (foreign language - Arabic language), the scale was applied in its initial form to (200) students from some Faculties at Zagazig University in order to verify reliability and validity, and after checking the reliability and validity, the scale was applied to final research sample, which consisted of (689) students from some faculties in The University of Zagazig in order to verify the research Hypotheses, and the most important results were indicated that the Factor analysis resulted in Six psychological structures: daily-life disturbance, positive anticipation, withdrawal, cyberspace-oriented relationship, tolerance and overuse, Alleviation of negative emotions, results were indicated that the level of smartphone addiction among university students is below average, the results showed no bias, (i.e., there is no differential item functioning for any item based on gender), revealed that the gap between the male and female groups was widening (according to “DIF CONTRAST”) at one item but without significance, and there is no bias, (i.e., there is no differential item functioning for any item based on study language), revealed that the gap between the foreign language and Arabic language groups was widening (according to “DIF CONTRAST”) in some items but without significance, and there is no statistically significant differences due to the variables of gender and study language on all dimensions of smartphone addiction scale.