This study is an attempt tofind the effect of four types of feedback(direct,underline,code,translation)on the writing performance of Iranian learners ofJapanese as a foreign language.In this research,we have tried to suggest new ways of correcting students’writing through giving different kinds of feedback in the process of learning to write.The study focused on the accuracy of using prepositions,adjective clauses and noun phrases as three grammatical structures.Learners,as participants of our study,were divided into experimental and control groups.Both groups were asked to write eight essays whose genre were descriptive.For each two different topics,they were given a specific feedback.The results showed that the feedback enhances the writing performance of Iranian learners of Japanese as a foreign language.In addition,although previous studies believed that giving feedback on the correct use of prepositions does not have any significant effect,the present study indicates that the use of prepositions changes for better through the types of feedback given to learners.