This study aims at analyzing the effect of elementary school learners' Big Five personality traits on their writing performance. Hence, data were collected on personality traits and writing performance, and descriptive statistics, correlation & regression analyses were conducted at an elementary school located at Seoul. Research findings are as follows. Firstly, as a result of analyzing a correlation between learners' Big Five personality traits and writing performance, conscientiousness, emotional stability, extroversion and openness from personality factors showed a positive correlation with writing performance, and agreeableness had a negative correlation. Particularly, conscientiousness and emotional stability formed a statistically significant correlation with writing performance. Secondly, the effects of learners' Big Five personality traits on writing performance are as follows. It showed that conscientiousness and emotional stability, sub-factors of personality had a statistically significant effect on the organization, a sub-factor of writing performance. 𝛃 of conscientiousness is .268, 𝛃 of emotional stability is .213, and the explanatory power is about 10%. Besides, among sub-factors of personality, emotional stability and conscientiousness had a statistically significant effect on the overall writing performance. 𝛃 of emotional stability is .185, 𝛃 of conscientiousness is .156, and the explanatory power is about 5%. Such findings generally confirm that Big Five personality traits have an inconsiderable effect on writing performance. As for Big Five personality traits, only conscientiousness and emotional stability showed a lower influence. More in-depth discussion is required on individual learners' traits influencing on writing performance.