This study aimed to reveal the ability of lexical use of married immigrant women residing in Korea for a long time by collecting their writing materials, based on the lexical complexity as its theoretical background. In summary of the results of this study, regarding the lexical diversity, immigrants used noun-concentrated words regardless of the topic of composition. Regarding the lexical density, the number of actual words realized was increased while the number of type was decreased. It shows that married immigrant women are repetitively using words in the same parts of speech regardless of the topic of composition. Moreover, regarding the lexical sophistication, most of the immigrants only used high-frequency words used in daily life, so that their ability of lexical use was no better than the elementary level. Especially, the result of Measurement lexical complexity shows that it is limited to learn words by itself in the natural learning environment just like grammar. And the lexical education should be considered not in the aspect of simple understanding, but in the aspect of production. Lastly, this study has a limitation of having few research samples. However, the significance of this study is to collect vertical data and also to objectively measure the lexical ability of married immigrant women through indexes of lexical density and lexical sophistication.(Dongduk Women’s University)