This study investigated whether orthographic consistency and individual learner differences including working memory (WM), first language (L1) background, and second language (L2) proficiency affect Chinese L2 learners' literacy acquisition. Seventy American college students in beginning or intermediate Chinese classes participated in a character learning-and-reading experiment, and completed WM tasks and an L2 proficiency test. In the learning phase of the experiment, participants were asked to master 18 unfamiliar Chinese characters of three levels of consistency--consistent, semi-consistent, and inconsistent. Then in the transfer test of the experiment, participants read 60 novel, artificial characters analogous to the learned characters. Significant consistency effects for learning and reading new characters were found, with no effects of WM and L1. In particular, an interaction effect between consistency and L2 proficiency found in the learning phase indicated that participants with higher L2 proficiency learned the fully consistent characters better and faster than those with lower proficiency. These results suggest that L2 proficiency facilitates awareness of consistency, enabling learners to learn novel characters faster and more accurately. The findings of this study are compared with the character acquisition of beginning L1 Chinese readers and with L2 learners' acquisition of other types of characters.