The English language is a catalyst for economic growth, modernization, and globalization. In this milieu, English language competency--defined as the practical ability to use English effectively in diverse contexts, encompassing linguistic, cognitive, and intercultural skills--is recognized as an essential skill (Amor et al., 2023). Research on English language competency among ethnic minority students is sparse, obscuring the dynamics between personal and environmental factors. We analyzed factors influencing language competency, examining the interplay across the theory's five system levels using 82 research papers published from 2014 to 2024. The three factors most commonly discussed were at the individual level (psychological factors), the microsystem level (teachers and family), and the macrosystem level (language policies, sociocultural influences, and identity). Our analysis also revealed the importance of conducting thorough studies at various levels. These include the microsystem level, which involves examining the interactions between teachers, families, and students and the challenges faced in practical cooperation between parents, educators, and students. Additionally, the mesosystem level, which focuses on digital learning tools, the exosystem level, which considers factors such as socioeconomic status and mass media, and the chronosystem level, referring to discrete shifts like switching from a monolingual to a multilingual environment, are also crucial areas of study. The study ends with research directions highlighting the necessity for a holistic examination of the factors influencing EFL learning among ethnic minorities, and the need for future research to include broader and more diverse samples for a comprehensive cross-cultural analysis.