: The purpose of this research is to describe: (1) the characteristic of the use of the register on outsiders in Surakarta, (2) the purpose of the use of the register on outsiders in Surakarta. This study uses descriptive qualitative method. The data sources are is the outsiders daily conversation and informers. Techniques for collecting the data use direct observation, interviews, and recording theoutsiders dialogue. Data validity test uses triangulation method and triangulation source. The data analysis technique uses interactive analysis which includes four components : (1) data collection, (2) data reduction, (3) data serving, and (4) drawing conclusion. The register characteristics of outsiders are (1) dominated by the use of Javanese, (2) having the shift and the change of the words meaning(3) having simpler form of language, (4) having the use of unapproppriate/ impolite words (5) having code switching and code mixing, (6) using a variety of intimate. The purposes of the use register on outsiders in Surakarta are: (1)to differenciate themselves from anothers outsiders community, (2) to show the respect among the outsiders, (3) to show the intimacy of the outsiders, (4) to emphasize the emotion and (5) to hide the meaning of communication from society. The conclusion of this research is that the characteristic and particular purpose of street child register is different from the characteristic and purpose of another society or community.