This research is to investigate the advantages and disadvantages of the use of mother tongue in the second language teaching which have both advantages and disadvantages to student. It has been widely advocated that insistence on English-only policy and the complete prohibition of L1 would maximize the effect of learning L2 but recent studies demonstrate that the appropriate use of L1 has a facilitating role in L2 classroom. This study attempts to demonstrate that the use of L1 in ESL classes does not hinder foreign language learning. The second language teaching using mother tongue, it is the better use of second language only one language. Because in the teaching process, must use the language to explain or summary to the student's understanding. The use of the language 1 only one language, may be appropriate in some situations, but must use different techniques to do this. So how direct language used in teaching English in the classroom. Depend on the type of the student in the early levels for children start learning to use language. But when in a higher level should reduce the role of the mother tongue for less. To ensure that students fully understand what to do, instructions should be given in L1 and the Use of L1 is beneficial to convey meaning and explain grammar. Furthermore, it is useful for students if they use L1 while comparing their answers in groups which will lead them to an Understanding of L2 better. In particular, in some cases where learning and teaching difficulties arise, in learning vocabulary fast and comprehension of difficult concepts both the teacher and the students need to use the L1. Therefore, the use of mother tongue in foreign language teaching cannot be avoided. the identifies the uses for L1: classroom management, language analysis, presenting Rules that govern grammar, discussing cross cultural issues, giving instructions or prompts, and checking for comprehension.in order to prevent the misunderstanding of the meaning of the New word, teachers should provide clear, simple, and brief explanations of meaning, especially in the learners' first language. Using L1 in L2 classes facilitates both Teaching and learning, aids understanding of ESL structures and inspires meaningful learning