China’s Standards of English is the national standard of English assessment in our country and a framework for teaching and learning, which can be applied in many fields of assessing, teaching and learning. The present study aims to apply China’s Standards of English to diagnose the writing strategy ability of the college students in China and thus provide prompt and accurate feedback for both teachers and students in writing strategy instruction. First, the present study developed a questionnaire for self- assessing targeting the college students. The questionnaire is adapted on a basis of the writing strategy sub-scale of China’s Standards of English from level 4 to level 8. Second, 287 college students answered the questionnaire when they finished a composition. Validation of the questionnaire was conducted by factor analysis. Last, correlation analysis, ANOVA and regression analysis were conducted to examine the relationship between writing strategy use and writing achievement, which proved that: 1) the writing strategy of college students can be interpreted by planning strategy, formulating strategy and revising strategy; 2) the writing strategy use is significantly relevant to writing achievement which means that the better the writing composition, the more writing strategy the students will be likely to use, and in general, students tend to use less planning and revising strategies than formulating strategies; 3) planning strategy, formulating strategy and revising strategy can make different contributions to the language, content, structure of the writing composition. Based on the results, suggestions of diagnosing feedback for writing strategy instruction for teachers and writing strategy improvement for students’ self-learning are provided.