Objectives: This study was performed to identify the effects of smartphone addiction on sleeping time and sleep deprivation among some college students. Methods: The study subjects were 287 students in a college who were using the smartphone, and data was collected by self-administered questionnaire. The used statistical analysis were t-test, ANOVA, Pearson``s correlation analysis and multiple regression analysis to find the association of smartphone addiction with sleeping time and sleep deprivation. Results: The smartphone addiction scores of study subjects were 32.9±6, and 17.1% of subjects was at-risk group and 5.6% was high-risk group in classifying risk groups. Mean hours of sleeping time were 6.4±1.2 and mean scores of sleep deprivation scale were 8.4±3.1. The smartphone addiction had negative correlation with sleeping time, but it was not statistically significant. However, it showed statistically significant positive correlation with sleep deprivation scale. As results of multiple regression analysis, the smartphone addiction was statistically significantly associated with sleeping time (β=-0.033, p=0.001) and sleep deprivation scale (β=0.127, p<0.001). Conclusions: This study showed the smartphone addiction in college students was negatively associated with sleep. It is necessary to perform the further researches and to develop the programs for solving the problems due to smartphone addiction.