The purpose of this study was defining the effectiveness of an authors made instructional model based on Robert C. Gardner's Integrative &Instrumental motivation in L2;A model which aims to improve motivation in Persian (Farsi)language learners(persian as a foreign language). For doing so a case study research design selected and after replying to a farsi version of Attitude/Motivation Test Battery(AMTB) (Gardner:1985) and also an individual questionnaire, one case, who is entitled here Y, entered in the study in a purposive sampling. Y was a 20 years old, chinese student, whose results of AMTB and interviews showed his motivation in learning persian language,is integrative one. The case was male and had passed a 240hours preliminary course of Farsi in 2012 & expressed interest in our study. Our instructional model had two different approaches for each motivational types(i.e.instrumental a& integrative one):a model which considered some strategieg for choosing the place of instruction,the media type, the words, contexts, writing subjects, listening and speaking materials in compliance with the instrumental or integrative motivation. The instruction started and lasted for a 16 weeks period. At the end of each week Y participated in a general Farsi skills exam(i.e reading, writing, listening and speaking skills) and the scores and also Y's own perspective on Farsi learning, were collected. The final results qualitative analysis showed a clear improvement in case's scores and also self-satisfaction about own learning during instuction and application of model. Based on our finding, it can be concluded that, presented instructional model for farsi learning of the studied case, Y, was effective.