This study investigated learner variables of Korean university students and explored the relationships of the variables to English language proficiency. Four instruments, the Strategy Inventory for Language Learning (SILL), the Perceptual Learning Preferences Survey (PLSP), the Beliefs about Language Learning Inventory (BALLI) were administered to sixty university students in Korea to identify their learner variables. Their English proficiency was measured by the Test of English for International Communication (TOEIC). The results of the study are as follows: the correlations between strategies and proficiency were significant while the correlations between styles and proficiency and between beliefs and proficiency were insignificant. The results suggested that strategies are the best predictors of proficiency, especially cognitive, compensation, and metacognitive strategies. The pedagogical implication from the results is that EFL courses should involve strategy training.