Background: This study was aimed to investigate the roles of the positive outcome expectancy towards smart phone use and well-being in smart phone addiction among adolescents.

Methods: A total of 1133 students (53% boys, 47% girls)were sampled from three junior high schools in Taiwan participated in the present study. All participants completed The Outcome Expectancy of Smart Phone Use Questionnaire, the Smart Phone Addiction Scale and the Chinese Well-being scale -short version."

Results: The levels of positive outcome expectancy of smart phone use were positively correlated (r = .37) with smart phone addiction scores. The well-being scores were negatively associated with smart phone addiction levels (r = - .14).By using hierarchical multiple regression analyses, the results showed that the interaction between positive outcome expectancy and well-being predicted smart phone addiction. The further analyses indicated that the positive outcome expectancy of smart phone use increased prediction in smart phone addiction among adolescents with higher scores in well-being;The well-being decreased prediction in mart phone addiction among students with higher positive outcome expectancy of smart phone use.

Conclusions: The high well-being could be the protective factor for adolescents from smart phone addiction among students with higher positive outcome expectancy of smart phone use; meanwhile, the low positive outcome expectancy could be the protective factor for adolescents from smart phone addiction among students with lower well-being. 

Key words: smart phone addiction, well-being, positive outcome expectancy toward Smart Phone, adolescents