Abstract: Objective To predict the incidence trend of typhoid and paratyphoid fevers in Yunnan province, and provide reference for the government in policy making. Methods According to the incidence data of typhoid and paratyphoid fevers in Yunnan from 2001 to 2010, the predicting model for typhoid and paratyphoid fevers incidence was established by using grey system theory to carry out predicting research. Results The grey model was X(k+1)=-245.5667e-0.1067k+270.2939. The goodness-of-fit test indicated that the precision (degree 1) was qualified (C=0.3420.35, P=1) and the grey model was capable in predicting the incidence of typhoid and paratyphoid fevers. Conclusion The predicting results indicates that the incidence of typhoid and paratyphoid fevers will continue to decrease in Yunnan from 2011 to 2014,but it is still necessary to strengthen the comprehensive prevention and control of typhoid and paratyphoid fevers, including health education and treatment management.