This study aims to investigate the process of acquiring Korean particles by Chinese speakers who have previously learned Japanese as the second language(L2). The paper divides Taiwanese learners(Chinese speakers) who have previously learned Japanese as an experimental group and a control group(those have never learned Japanese), conducting experiments based on the questions related to Korean particles to examine the error patterns made by the learners. Through experiments conducted after 72 hours of learning for both groups, the study analyzes overall scores, common patterns of particle errors within each group, error frequencies, and the influence of the second language on the third language(L3). The findings compare the error patterns between the experimental and control groups, highlighting differences and their implications, and analyzing the reasons for these differences. Based on the findings, the study emphasizes the significance of considering learners’ prior language learning experiences in understanding and addressing error patterns in third language acquisition, providing insights for language acquisition.