TikTok, a social media platform known for its transformative impact on language. Nowadays, lexical changes are widely observed on TikTok, where lexical change itself refers to the phenomenon of words and phrases undergo modification in their form, meaning, or usage. This qualitative study explores various forms of lexical changes among eight PBI students at UIN Ar-Raniry who are active TikTok users and have completed the sociolinguistics course. The research used two techniques in collecting the data, text analysis and semi-structured interviews. The findings of this research identified several types of lexical changes produced by PBI students on TikTok, such as borrowing, compounding, initialism, blending, and clipping. Additionally, the study explored the reasons behind PBI students' use of lexical changes on TikTok. These reasons included expressing social identity and creativity, adapting to sociolinguistic influences, responding to globalization and language contact, and participating in generational language shifts. By exploring lexical change on TikTok, this study contributes to broader discussions on language evolution and identity in digital communication environments.