Abstract: Objective The study was conducted to assess the quality of the network reporting system of communicable diseases in Yunnan, providing evidence for the improvement of report quality.Methods Routine statistical analysis and evaluation of four indexes associated with the report quality was performed for the network reporting system.Results A total of 174 659 cards were reported through the network reporting system from January to December in 2008.The rate of report in time was 93.01%, the rate of verification in time 98.49%, and the rate of duplication 0.0025%.The omission rate was zero in county areas.The composite index for four indexes of report quality was 2.12%.Conclusion The report quality was compromised due to procrastination of report and verification during vacation; the management standards and coordination of the report system for specific diseases constituted the other influential factor.