This study establishes a construction early warning system for construction works. The system uses computer to integrate related data to predict when, where and what kind of disaster will be happened. It can give the officials enough reacting time and propose a suitable countermeasure for the reducing of construction disaster. This research uses the powerful computing capability of the computer and relational database to establish the basic framework. Then compare with the similar disaster cases that had happened and through the analyzing and comparing for screening and evaluating the potential possible construction disasters that may happen in specific period and location. The system also can list out all the preventive measures for the various kinds of disasters, according to the potential hazard of influence and importance, to help construction inspectors with its prevention works.