Abstract name: dilla meilani nst student no. : 1506102020020 department/program : english education/undergraduate title : an analysis of word formation in indonesian slang words in ria ricis youtube vlogs keywords: slang words, slang types, slang functions, and word formation. language as a means of human communication in everyday life involves feelings and emotions that are usually expressed through slang words. this study focused on finding out and describing the types and functions of indonesian slang words found in ria ricis youtube vlogs. in conducting this research, a descriptive qualitative approach was used. the data source was ten video blogs posted on ria ricis’s youtube account and the instrument was the researcher herself. the data were collected through documentation procedures where the videos were watched repeatedly to observe the slang use phenomena. then, the data which are identified as slang words were identified were divided into types