The technique of fictional portrait in biographies has long been a sensitive issue in the field of biography studies. Gibran Kahlil Gibran is an excellent biographic work by Lebanese American migrant writer Mikha’il Nu’imah portraying the life of Gibran，the soul and leader of Arab American migrant literature；hence it has been an important reference for researchers on the life story of Gibran as well as his literary and artistic works. Yet this biography had caused much dispute because of its portrayal of the inner conflict of the poet and its use of technique of fictional portraying. This article discusses the fictional portraying in Gibran Kahlil Gibran based on theories of biographic study，so as to serve as a reference for the studies of Arabic biographic works.