It is important to understand the functional activity of the human brain during the resting state by analyzing the functional connectivity between the regions. The resting-state brain functional network was constructed based on the complex network theory. The result of analyzing the structure and topology of network showed that the resting-state brain functional network was a sparse and scale-free small-world network. Furthermore, a probabilistic mixture models was introduced to detect the community structure, which revealed 10 sub-networks underlying the network, including the visual system, auditory system, motor system, and default-mode network, as well as the brain regions associated with the executive and working memory function. Our findings suggested that the resting-state functional network of human brain was composed of these relatively independent and overlapping sub-networks, and the precuneus and cingulate gyrus played important roles in dispatching and transferring information of network.