This study investigates lexical errors in spoken Korean made by Chinese students learning Korean and illustrates the causes of these errors in order to prevent those errors from taking place in the future. In this study, 738 recorded files produced by 136 subjects have been analyzed. 1053 lexical errors identified have been categorised into 18 types of errors, which include literal translation, code-shifting, noun error, semantic similarity, formal similarity, pronunciation, overgeneralisation, omission and addition, word coinage, wrong choice, etc. According to the source, types of errors have been classified into four main categories: 1. Interlingual transfer errors (3 types); 2. Intralingual transfer errors (12 types); 3. Combination of both (1 type); 4. Unique errors (2 types). The four main categories of results of error ratios were as follows: 66.7% intralingual, 20.3% interlingual, 9.2% unique, and 3.8% combination. However, among the types of errors, the most frequent type was errors of literal translation in all levels. Thus, it is important to illustrate the causes of lexical errors, especially those caused by native tongue-interference. The results of this study would provide Korean instructors with data and interpretations of lexical errors made by Chinese learners. Moreover, the findings of this study would be useful for designing lexical education programs.