Abstract: Objective The present study was conducted to compare the quality of the direct network reports on the legal infectious diseases in the first half year of 2005 with that in the first half year of 2006 in Taiyuan City in search of the factors affecting the quality of direct network reports for the improvement of quality. Methods The data on the notifiable infectious disease reported by the centers for disease control and prevention (including the sanitation and anti-epidemic stations) of individual districts and counties (cities) and other medical facilities (blood collection and supply institutions, health quarantine facilities) under their jurisdiction in the first half year of 2005 and in the same period of 2006 in the City of Taiyuan were obtained through The Management System for Reporting Information of Disease Surveillance, a sub-system of The Information Systems for Disease Control and Prevention in China. Excel software was used for the analysis and comparison of the relevant parameters. Results Compared with 2005, the timeliness and completeness of reports on the notifiable infectious disease in 2006 in Taiyuan were improved, but the timeliness of revision and the accurateness of reports decreased. Conclusions The quality of reports on the notifiable infectious diseases in Taiyuan needs to be improved. Training and technical instruction of the personnel in terms of epidemic reporting in the institutions should be strengthened. Only when the responsible and qualified reporters and managers shoulder their own responsibilities can the quality of infectious disease reports be ensured.