Objective To study the seasonal characteristics of cholera, Hepatitis A, bacillary dysentery, kidney syndrome hemorrhagic fever (HFRS), and epidemic encephalitis B and rabies in Nanchang from 1998 to 2007. Methods The seasonal characteristics and the peak morbidity time distribution were analyzed respectively by the Concentration degree analysis and the Circular distribution. Results In terms of seasonal characteristics, cholera was strictly and epidemic encephalitis B stronly distributed, while bacillary dysentery had some indicdtions and Hepatitis A and HFRS were not obvious. All the above diseases had their peaks: cholera on August 3, and epidemic encephalitis B on July 8.95% of credible time zones were from June 12 to August 24 and April 24 to September 21 respectively. Conclusions Hygienic publisizing and disease surveillance should be strengthened, especially during morbidity peak time.