Management and monitoring the health condition of underground utilities are essential in the process of sustainable urbanization development,as our daily necessities such as water,gas and electricity supplies are delivered through very complicated networks of pipes and cables underground.Regarding the management of water pipes,if their health condition is not regularly and properly monitored for preventive measures to be carried out in advance,the leakage of water pipes may cause road and slope collapse and hence lead to traffic jam and inconvenience to public,and more seriously fatality and property loss.However,there are no unified rules in Hong Kong on the interpretation of the health condition of utilities from pipe condition survey data.As the judgment is largely based on experience,it is unavoidable that subjective interpretation,particularly those cases with fuzzy results on for example site inspection,visual assessment based on photos and video recording may lead to different opinions.In this paper,the development of an expert system to enable collective decision making on the fuzzy results,and together with other assessment results to rank the overall health condition of drainage and sewage pipes based on the continuous tracking on the Utility Health Index(UHI)is introduced.The system is being tested in the Utility Info using real project data for further improvement.The long term tracking of the UHI and the site inspection results used for calculating the UHI can provide a fuller picture on the health condition of different sections of the pipe network.With the continuous monitoring of the pipe condition by the expert system,the potential problems of pipes can be continuously analyzed and identified,for the maintenance logistics and precautions to be planned and implemented more effectively. Management and monitoring the health condition of underground utilities are essential in the process of sustainable urbanization development, as our daily necessities such as water, gas and electricity supplies are very through networks of pipes and cables underground. Regarding the management of water pipes, if their health condition is not regularly and properly monitored for preventive measures to be carried out in advance, the leakage of water pipes may cause road and slope collapse and hence lead to traffic jam and inconvenience to public, and more serious fatality and property loss. However, there are no unified rules in Hong Kong on the interpretation of the health condition of utilities from pipe condition survey data. As the judgment is largely based on experience, it is unavoidable that subjective interpretation, particularly those cases with fuzzy results on for example site inspection, visual assessment based on photos and video recording may lead to different o pinions.In this paper, the development of an expert system to enable collective decision making on the fuzzy results, and together with other assessment results to rank the overall health condition of drainage and sewage pipes based on the continuous tracking on the Utility Health Index ( UHI) is introduced. The system is being tested in the Utility Info using real project data for further improvement. The long term tracking of the UHI and the site inspection results used for computing the UHI can provide a fuller picture on the health condition of different sections of the pipe network.With the continuous monitoring of the pipe condition by the expert system, the potential problems of pipes can be continuously logged and identified, for the maintenance logistics and precautions to be planned and implemented more effectively.