Second language acquisition (SLA) has been one of the central topics in cognitive science. Various theories regarding the SLA process have evolved and have been a subject of debate over the years. With a critical review of the competing theories of cognition and language development, this paper examines the differences between L1 and L2 acquisitional processes and then proposes a model of SLA process from a cognitive information-processing perspective. The pedagogic implications of this model are also discussed. Second language acquisition (SLA) has been one of the central topics in cognitive science. Various theories regarding the SLA process have evolved and have been a subject of debate over the years. With a critical review of the competing theories of cognition and language development, this paper examines the differences between L1 and L2 acquisitional processes and then proposes a model of SLA process from a cognitive information-processing perspective. The pedagogic implications of this model are also discussed.