This study about the analysis of the lexical errors translating English text and also to find out the causes of doing the errors. In the lexical errors the there are two causes of the errors, namely: interlingual and intralingual. In writing this research, the writer did a descriptive method. Besides, the writer also made a test toward students of English depart of 2006/2007 academic year of language and art faculty of HKBP Nommensen University. The writer asked the students to translate two English texts and the data from the result of the translation. Finally, from the data gathered, the writer can made a conclusion that the causes of error of the lexical errors also give effects to the result of the translation.