The study is based on emergency writing instruction questions, we measure writing ability and writing creativity of pupils and assay these abilities development, we choose revising question to study because this is a frail programmer in writing instruction in elementary school, and focus on this question we carry out experiment about learning and teaching. Finally, we are training pupils' writing ability in normal writing instruction. All this contents was separated nine in this paper.Part I : Introduction.Around the study had chosen contents the author review on psychological researches of writing about two decades. The author summarize and evaluate researches about structure of writing ability, writing measurement studies and outcome of revising psychology, all the same time sum up writing instructions and methods of training writing ability to acquire successful and failure experiences.Part II : Compiling primary students' writing ability test and writing creativity test.The writing ability test is formed of six kind abilities, there are understanding title ability, deciding topic meaning ability, choosing material ability, arranging material ability, expression ability, revising ability. The author defined the six kinds abilities on operation level and considered the requirements of syllabus about writing instruction on 3-6 grades in primary school, then compiled primary students' writing ability test that fit to individual test. The test structure of the primary students' writing creativity test is based on same abilities structures writing. But the author think the revising ability is notimportant in writing creativity so only test other five kinds abilities. The author respective tested 3-6 grade pupil several times, finally, the formal test that used preparation test was accomplished. The author taken up preparation test and checked the science quality of the test. The result indicate the test has good science quality so normal test keep the content of preparation test. There are 28 item make up the normal writing ability test, it has good reliability and validity .The item analysis indicate it has good distinction, the test is coincidence with requirement of measurement theory. There are 6 item make up thenormal writing creativity test.Part III: The developmental study of pupil' writing ability.The author choose students in varying schools including lower primary school, common primary school and good primary school. Let them take part in primary students' writing ability test and writing creativity test. All of effective paper is 563. The result analysis indicate the students' writing ability have significance difference in three level school. The writing ability of students in common and good primary school is best than lower school students. Common and good primary school has no difference. Analysis from component of writing ability indicate understanding title ability, arranging material ability and expression ability and deciding topic meaning ability have same tendency as a whole. Choosing material ability and revising ability have interaction in school and grade.The students' writing ability has significance difference among grades. The development of primary school student' writing ability shows upswing tendency in whole. The developmental speed is not equilibrium and shows three stages. : The first stage refers to 3-4 grades, developmental speed of writing ability is faster. The second stage refer to 4-5 grade, the developmental speed of writing ability is slower up. The third stage refer to 5-6 grade, the developmental speed of writing ability is faster. The 4 grade is key period of writing development. Analysis from component of writing ability indicates understanding title ability, deciding topic meaning, arranging material ability and expression ability have same tendency as a whole. Choosing material ability and revising ability have interaction between schools and grades and shows complicated situation.The students' writing ability has significance differen