Ideation is the special intellection of human.It is the indirect and general reflection of the objective reality on the basis of the language materials.The application Writing is the production of the writer's ideation so the perfect knowledge and brainpower is necessary for the writer.The ability of thinking is the key and essential in the construct of ideation and it goes throng all the course of the application writing.We must cultivate the ideation of the students to improve their ability of thinking so as to improve the ability of the application writing of the students.