The seven novels of "Harry Potter" series written byca British writer J.K.Rowling is a great success, leading to the movies (based on the novels) a big hit around the world, which has not only created enormous social and economic benefits, but has also become a culture phenomenon, a culture consumption within the past ten years.In this essay the writer analysed the co-prosperity of interdependence and mutual promotion between novels and movies from the aspect of their benign support, the two-way interaction and the art amplification effect unique in movies.