Lee Eunha・Choi Eunjeong The present research aims to examine the longitudinal relationship among intrinsic motivation toward Korean, academic self-efficacy in Ko- rean, Korean teaching activities perceived by students, the time spent on studying Korean, the ability to understand Korean lessons, and Korean academic achievement using latent growth modeling. We used the longi- tudinal data of Time 1 (2005) to Time 3 (2007) collected by KEDI (Korean Educational Development Institute) since 2005. The results showed that (1) the slope of change in intrinsic motivation and academic self-efficacy decreased during the three year period; (2) as the rate of change in the perceived teaching activities increased, intrinsic motivation and academic self-efficacy also rose; (3) the slope of change in than the initial state of intrinsic motivation had a greater impact on both rates of change in studying time and the ability to understand lessons; and (4) the effect of the initial state of academic self-efficacy on Korean academic achieve- ment at the first grade was positively mediated by the initial state of abil- ity to understand lessons.