Age has always been an important factor in studying second language acquisition. Marinova-Todd points out three mis-conceptions about research in support of CPH and disputes the existence of a Critical Period in L2 learning. Hyltenstam&Abraha-msson refutes Marinova-Todd’s“three misconceptions”. By contrasting and comparing the views and evidence from the two pa-pers, the present author analyzes the differences among various claims on the rate of learning and different brain organization , as well as the possible causes for the disagreements.