Based upon analysis to current research status of desertification assessment indicator systems, a new viewpoint that takes vegetation as main factor for desertification assessment is brought forward. Taking Mu Us Sandland as a research example, by analyzing desertification characteristics in different land types, the succession series of the main indicative vegetation community is put forward. Based on the field observation data about regulations of windblown sand movement and sand-driving wind, the protecting effect of vegetation on land surface is studied, and the vegetation cover grading standards for windy erosion desertification assessment are put out.