We examined how perceived parenting style, friendship satisfaction, and academic motivation influence the addictive use of smartphones longitudinally. We utilized the panel data (from 2010-2012) of Korean children and youth panel survey of the National Youth Policy Institute. Data were collected from 2,376 individuals in the first year (boys: 1,241, girls: 1,135), 2264 individuals in the second year (boys: 1,180, girls: 1,084), and 2,218 individuals in the third year (boys: 1,167, girls: 1,051). Results of the multivariate latent growth modeling indicated that higher democratic parenting (warmth, supervisory, and rational explanation) was related to lower addictive use of smartphones. And, the more perceived democratic parenting was high, the more academic motivation and friendship satisfaction were high. Also, friendship satisfaction and academic motivation negatively influenced the addictive use of smartphones; the more friendship satisfaction and academic motivation increased rapidly over time, the more the addictive use of smartphones decreased over time. These results imply that affective and supervisory parenting can positively impact peer relationship and learning motivation, and the satisfaction of peer relationship and academic motivation can be protective factors for the addictive use of smartphones.