This study aimed to investigate whether there was a significant difference between extroverted and introverted students in terms of speaking achievement at speaking I class of English Education Department in Halu Oleo University academic year 2016/2017. The design of this study was quantitative comparative study. The population of this study was the entire speaking I class in English Department of Halu Oleo University in academic year 2016/2017 which consists of two classes in total of 112 students. The sample of this study was chosen randomly of all the population by using Questionnaire of Eysenk Personality Inventory. The instruments of the study were questionnaire and final score of speaking 1 subject. The researcher collected the data by using questionnaire of Eysenck Personality Inventory to get the data associated with extroversion/introversion and final test score of Speaking I subject to get data about students‟ speaking achievement. To analyze the result of the study, the researcher used Independent sample T-test in SPSS 16.0 for windows. Independent sample t-test was conducted to determine whether there is a significant difference in the performance of the extraverted and introverted students on their speaking achievement. Independent Sample T-test was showed the value of Sig.(2-tailed) = 0.502 with α = 0.05, H0 was accepted and H1 was rejected. It is because of sig. (2-tailed) value is higher than α value. The result of this study showed that there was no significant difference between extroverted and introverted students‟ speaking achievement at speaking I class of English Education Department in Halu Oleo University academic year 2016/2017.
KEYWORDS: Extroversion, Introversion, and Speaking Achievement.