This study aims to describe the form of slang based on changes in the phonological structure of slang vocabulary and the process of morphologically forming slang vocabulary, types of slang meanings, and the function of using slang vocabulary contained in WhatsApp groups among teenagers Sanggrahan Sukoharjo district. The method used in this study is a qualitative descriptive method. The data was collected by means of screenshots of conversations in the Sanggrahan youth group on WhatsApp social media, and a recording of the slang vocabulary used by the Sanggrahan youth in Sukoharjo Regency in the WhatsApp group. The data analysis technique used in this research is the distributional technique. The results of this study contained 56 slang vocabulary used by teenagers at Sanggrahan Sukoharjo Regency in the WhatsApp group. In the data, there are first, the form of slang there are two changes, namely changes in the phonological structure of slang vocabulary and the process of morphological formation of slang vocabulary, secondly the meaning of slang vocabulary, and the third type of function of using slang vocabulary. There are two meanings contained in this study, namely denotative meaning and connotative meaning. However, in research, denotative meaning is used more prominently than connotative meaning. The types of functions of slang vocabulary used in this study include emotive functions, conative functions, referential functions, and fatigue functions.