This research was intended at analyzingof students errors in pronouncing English words at SMAN 1 Parigi Tengah,and finding the most problematic tense-lax sound for the students and factors made them could not produce words correctly. In this research, the researcher did not apply any method. It is called descriptive research. The population of this research was all member of class IX B at SMAN 1 Parigi Tengah consistingof 25 students. Theinstruments of this research were oral test and interview. The researcher found that the most problematic sound for the students was /ɜ:/. The students\u27 errors in producing this sound was 96% in initial and final position while in medial position all of them could not produce this sound correctly. It was caused by two factors,namely internal and external factor
