ABSTRACTrnThis study is entitled : “AN ANALYSIS OF GRAMMATICAL ERRORS IN THE TRANSLATION FROM BAHASA INDONESIA INTO ENGLISH OF THE EIGHTH GRADE STUDENTS OF SMP NEGERI 1 KUPANG IN THE SCHOOL YEAR 2012/2013”. It aims at answering questions: 1) what are the grammatical errors that might occur in the student‟s translation? 2) What might be the most frequent errors in the student‟s translation? The objectives of the study are as follows: 1) to find out the ungrammatical items in the students translation. 2) To find out the most frequent grammatical errors that occurs in the student‟s translation. The writer classifies the students grammatical errors based on Linguistics Category Taxonomy. The method applied in this study was descriptive method and the instrument used was in form of translation. The writer asked the students to translate the short story written in Bahasa Indonesia into English. There were 15 students taken from Eighth Grade especially class VIIIF as the subject of the study. The result of the analysis showed that the errors committed by the Eighth Grade Students of SMP Negeri 1 Kupang in their translated a short story were noun phrase (23.43%), verb phrase (30.72%), verb and verb construction (11.45%), word order (17.18%) and some transformation (17.18%). The most frequent error is Verb phrase. Based on the result of the study, the following is the suggestion for the teacher: to teach and really pay attention to the grammatical aspects especially in tenses, verb, noun and preposition. For the students: the students should master the grammatical aspects and really learn on how to translate sentences by considering the grammatical aspects, especially in tenses, verb, noun and preposition