Code switching is the process of shifting from one language code such as shifting of language or dialect of the other, depending on social setting or context of the conversation. Wardaugh (2002) stated that code switching can have an effect on language varieties in the situation of a single conversation when a speaker masters between two or more languages. An effect on language varieties implies with interactions between local people and foreign tourists that usually occur in the area of transportation services, it related to the pedicab driver services to having communication used English language to be able to facilitate communication. However, the phenomenon based on observation conducted was the pedicab drivers try to use their sub standard English skill to communicate with their passenger. This situation finally affects their communication to switching code. This study discussed about the use of code switching. The aimed of the study are to find out the factors that cause the pedicab driver used code switching while their communicate with their foreign tourist passenger. This study conducted at Malioboro Street Yogyakarta. This study used three pedicab driver at Malioboro Street as a participant. Underpinned by qualitative method, the study used observation and interview to gain the finding of this research. The data obtained that there are two factors that cause pedicab driver used code switching, namely the topic of the conversation and lack of vocabulary mastery