Software defects exist in all stages of the software life cycle.The current software defect assessment methods generally investigate only a few kinds of properties,most of which just make a qualitative assessment.In this paper,the authoritative defect databases are introduced.By the relevant databases,the corresponding properties that have comparatively great impact on the software defect are identified.Based on the analysis, the corresponding properties are quantified by applying the method of expertise,and a quantitative software assessment method is presented,which provides an effective reference for subsequent software repair.