This research aims to (1) find out the differences in segmental features between Banyumas dialect and English, and (2) describe the extent to which Banyumas dialect influences students’ English pronunciation.
The population of this research is tenth-grade students of SMA Negeri 1 Banyumas. The sample is chosen by purposive sampling. The researcher takes 56 students from two classes, 36 students of X IPS 2 and 20 students of X MIPA 1, as the sample of the research. However, for the purpose of organizing the data, the researcher reduces the data that did not fulfill the needs. They are the data from the students who are not originally from Banyumas and do not use Banyumas dialect in their daily communication. The researcher selects 30 students. This research used descriptive qualitative method. The data are collected by means of document analysis, questionnaires, pronunciation test, and observation.
The results show that (1) there are some differences in segmental features between Banyumas dialect and English. The differences are that some English sounds resemble Banyumas dialect sounds, some English sounds are absent in Banyumas dialect, and some Banyumas dialect sounds are absent in English; and (2) Banyumas dialect gives a negative influence toward students’ English pronunciation. There are many errors found on students’ pronunciation test. The errors are caused by the way Banyumas people read aloud, some English sounds resemble Banyumas dialect sounds and some English sounds absent in Banyumas dialect sound system.

Keywords: Banyumas dialect, pronunciation, sound system.