Abstract: Different from the classical epidemic models, the infectivity of a node is decided by its actual betweenness从 in the epidemic model based on traffi}flow other than degree k. Utilizing the mean-field theory,we proposed a modified SIS epidemic model based on traffi}flow. With this model,taking MIP route as an example,we re-studied the relation- ship between the spreading probability召，the traffic generation rate } and the epidemic threshold八，the stationary densi- ty of infected nodes p considering the scenarios in which the delivery capability of the nodes is bounded or unbounded.

Key words: Complex networks, Epidemic spreading, Susceptiblcinfected-susceptible model, Actual betwecnness