Abstract: Two experiments were conducted to investigate the mechanisms of secondary tasks during implicit sequence learning, in which different secondary tasks were used in each experiment. Ninety-six school students participated in these experiments (48 in each). The first experiment concerned with the effect of the secondary task and the sequence structure on the implicit sequence learning. The running-count was used as a secondary task. More difficult secondary task, tone-counting, was used in the second experiment to test the effect of the attention on the implicit sequence learning. The results show that: (1) The mechanism of implicit sequence learning is a pair-wise association mechanism, which forms associations between adjacent items. (2) The secondary task reduces the adolescents’ implicit sequence learning, the reason of these effects is not that the secondary task distracts the attention, but they disrupt the organization of the items in the sequence.

Key words: implicit sequence learning, secondary task, learning mechanism, attention