Abstract: Study of complex networks becomes a hot research topic. Complex networks arc applied to many applications such as engineering technology, society, politics, economics, medicine and management. Many scientists paid much attenlion on structures and dynamics of complex networks. Epidemic spreading in complex networks is one of the most important aspects. hwo classical complex network models, small world network model and 13A scalcfrec network modelwere studied in this paper. SIR spreading model was used to simulate the epidemic spreading and the spreading threshold, and to study two immunization strategics, stochastic and target, how to influence the spreading threshold. Spreading and controlling of H1Nl were simulated in the non-immunization case as well as in the stochastic and target immunizalion cases. Simulation results demonstrate that target immunization can restrain the spreading of epidemic effectively.

Key words: Complex networks,Epidcmic spreading,SIR model,Immunization strategies,Simulation