This study analyzes the chaos emerging mechanism through using logistic model according to the nonlinear character of Chinese real estate business cycle. The chaos emerging hypothesis is validated by the data in Chinese real estate market through nonlinear regression method. On the basis of comparing the different characters before and after entering the chaotic state, it can be found that the real estate bubble is prone to expanding and even breaking in chaotic field. And the main control factor is price-elasticity index of demand.

Building energy efficiency economy system is a complex adaptive system comprised of multi beneficial agents that their inner and outer relationships affect the system developing orientation together. This paper researches on the co-evolvement mechanism among different system agents using Multi-Agent System and simulation methods. After analyzing the characters and behaviors of different agents, SWARM simulation simulates the future tendency on executing building energy efficiency policy and efficiently solves the limited historical data.

The statues and problems of information systems about constructing projects management in China were presented in this paper. Combining with the development of information systems about constructing projects management in USA and Singapore, the author applied analogism approach to analysis the feasibility of integrating these management information systems in China, and pointed out it is the effective way to destroy Information Islands in E-government systems. And the author gives advices about the integration ways, which include two ways: one is project (object)-oriented for the need of government management and servings; the other is services-oriented for producers and consumers.

In today’s China, on the one hand, due to the process of rapid urbanization, the demand for building is increasing.On the other hand, because of the improvement of people’s living standard, the requirement of living condition is increasing rapidly. These two factors lead to the proportion that building energy consumption accounts for in society’s total energy use increase. Building energy efficiency becomes an important part of energy conservation. However, what is the tendency of China building energy consumption? What about the potential of building energy efficiency? This paper analyzes the demand factors of building energy efficiency, forecasts the further tendency of building energy consumption in China. Basing on this research, the author analyzes the results of implementing the measures for building energy efficiency, forecasts the potential of building energy efficiency in China, and provides the theoretical foundation for the country’s building energy efficiency policy.

Building energy efficiency is an important field in energy efficiency. In China, building energy efficiency, as an important link in realizing the country’s energy strategy, has been listed by the National Development and Reform committee in the 11th “Five Year Plan” as one of the ten key energy efficiency projects. Building energy efficiency belongs to the field where the market mechanism doesn’t work and it should be guided and adjusted by the government’s policy, which demands strong support from laws and regulations. Yet, the legal system concerning the building energy efficiency is not complete, which has become an important factor that limits the development of building energy efficiency. The paper analyzes China’s existing legal system of building energy efficiency and points out specific problems and incomplete places with it. Aiming at the needs of building energy efficiency at present in China, the paper points out that the legal system of building energy efficiency can be perfected from four aspects: The fundamental law in energy efficiency, “Energy Efficiency Law”, the primary law in the building industry, “Construction Law”, the administrative regulation, “Administrative Ordinances for Building Energy Efficiency” and the departmental regulation, “Administrative Regulations for Civil Building Energy Efficiency”. The paper puts forward suggestions of modifying, establishing, or revising the four legal documents and bringing them into agreement and thus providing practical legal support for carrying out the work of building energy efficiency in China.