关键词: 社会网络, 平均场理论, 行为扩散, 门限值

Abstract: In our everyday social life, there exist many scenarios that users are affected by each other, and decisions are made collaboratively. This paper deeply investigates the behavior diffusion model and diffusion process in social network, based on mean-field theory. A specific diffusion model is desiged that can accommodate the impact of three factors on user’s probability of adopting one specific behavior：the absolute number and the ratio of neighbors adopting the behavior and the number of her total neighbors. Based on mean-field theory, the diffusion process is analytically provided, and the effect of network structure on behavior diffusion is also given. The necessary condition（critical threshold） for widespread diffusion is analyzed. The simulation results verify the theoretical analysis.

Key words: social network, mean-field theory, behavior diffusion, critical threshold