Abstract: Infectious diseases incessantly threaten human beings for a long time. Many researchers pay much attention on the spread of epidemics, such as spread model, threshold spread rate, and affecting factors of spread, etc. Different initial infected individuals in the network how to affect the disease spreading was studied in this paper. Five initial infected individuals selecting methods were analyzed and two largescale undirected networks were used to simulate the disease spreading under different initial selected individuals. Simulation results demonstrate that the spread rate and the affected population size arc related to initial infected individuals as well as network structure. I}hc results can offer some valuable suggestions on disease controlling.

Key words: Epidemic spreading, Complex network, Initial infected individuals, Disease controlling