This study aims to examine the influence of personality on second language learning.The whole study was based on the researcher’s regular interviews with two ESL Chinese students and the observation of their performance during their first semester.Additional data was collected via a simplified Myers Briggs Type Indicator(MBTI)and interviews with their teachers and a native speaker of English.Overall English proficiency was assessed using two Institutional TOEFL tests and their current GPA during their ESL studies.A positive relationship was found between extraversion and spoken English while a slight but passive correlation emerged between extraversion and overall English achievement.