The primary objectives of this study were to shed light on social networking service (SNS) usage, and to investigate theeffect of SNS usage on university students' meaning in life and satisfaction with life. In this study, 146 students in the 3rd gradein a university in Tokyo completed a set of questionnaires. The instruments included a questionnaire on the usage and intendeduse of SNS, the Meaning in Life Questionnaire( MLQ)( divided into presence of and search for meaning in life factors)( Stegeret al., 2006) and the Satisfaction with Life Scale( SWLS)( Diener et al., 1985). Many students used the SNS LINE and Twitterto communicate with their friends. A covariance structure analysis indicated that LINE had a significant direct positive effecton the "presence" factor; and a significant indirect positive effect on the SWLS score, mediated by the "presence" factor.Additionally, communication with friends, and the sense of the achievement of playing a game, had a significant direct positiveeffect on the" search" factor.