In recent decades, as an important factor in second language acquisition (SLA), language aptitude has attracted more and more attention. Many scholars such as John Carroll, Skehan, Bialystok and Frohlich have proved that language aptitude has great impact on second language acquisition and can predict language learning effect. Using Modern Language Aptitude Test (MLAT), this paper mainly analyzes the influence of language aptitude on EFL learners in second language acquisition. Therefore, the author chooses some EFL students at the research subject, and adopts some methods (eg: interview) to survey their basic situation of foreign language learning. After that, the data collected are analyzed by SPSS, a statistical software. From those data, we learn about how language aptitude influences foreign language learning in the process of second language acquisition. Based on these results, the author finds out the relationship between language aptitude and teaching and then proposes several suggestions on how to teach efficiently when facing EFL learners.