The planning and implementation of Expo 2010 Shanghai China is a very complex mega- program system, and all missions and activities must be effectively coordinated, especially in time control. How to establish time control system effectively and efficiently is one of core issues: Meta-synthesis is a theory of complexity sciences which is put forward by Qian Xuesen, China. Based on this theory, the paper studies on how to control time objectives system of Expo2010. Firstly, by a structured approach, the time objectives system is broken down three streams, which are exhibition & participation, construction & operation preparation, and promotion & event. Under this breakdown structure, the paper analyzes the construction period subsystem. Secondly, by MSM (Multistage network planning method), three hierarchical time plan networks are put up, which are milestones for the Bureau of Shanghai World Expo Coordination, outline plans for construction program management headquarters which is representative of the government, and detailed plans for project management departments, and then the construction period subsystem is realized in Enterprise Project Management System (ie. Primavera P3). Besides, organization and management measures are described. This systematic method of time control in mega construction programme management could be used for other large-scale, global, non-commercial Expo, or other similar programs.