中文摘要：

受传统行政法影响，行政法体系基本上沿袭了以行政行为为中心建构的理论体系。公私合作背景下，合作行政兴起，传统行政法基本原则、行政行为、行政组织法、行政任务履行责任方式等面临冲击，行政法体系需从合作原则的建构、赋予私人组织行政主体地位、行政契约法律地位的确立、国家担保责任的建构等方向作出回应，以适应公私合作行政新形势的发展需要。

英文摘要：

Affected by the system of traditional administrative law, the system of administrative law basi- cally follows the theoretical system which centers on administrative acts. Under the background of public- private cooperation, cooperative administration is rising. The basic principles of administrative law, ad- ministrative behavior, administrative organization law, administrative tasks, ways to fulfill its responsibil- ity, all theses are facing impact. In order to adapt to the needs of the development of public-private cooper- ative administration in new situation, the system of administrative law need to timely respond in these ways ： to construct cooperative principles, give administrative status to private organizations, establish law status, of administrative contract construct guarantee responsibility.