Abstract: This paper establishes DEA model for performance evaluation of alliance members from the efficiency point of view and analyzes changes of members’ performance before and after alliance through a technological alliance in Jiangsu Province. We find that forming of alliance can enhance performance of the individual and the union. Then we use principal component method to evaluate performance of members after the establishment of alliance. We use the grey related method to identify factors that affect performance and obtain the sorts. Technical inputs associate with the enterprise performance mostly