Abstract: With the frequent adding and escaping of nodes in supply chain network being taken into account, the scalefree characteristics of such networks is studied. For this purpose, the BarabasiAlbert (BA) model is modified to describe the system. With the modified BA model, the probability distribution of an enterprise nodes link degree in the network is analyzed. Results indicate that only a minority of core firms can capture the great majority of links from other firms and the probability distribution of the link degree is inversely proportional to its link degree. Also, when the nodes of firms are synchronously increases and deleted, the link degree probability distribution of nodes in the supply chain network follows power distribution with parameterγ(1<γ≤2). The results are helpful for largescale enterprises in strategic management in the supply chain.

Key words: supply chain network, scale-free network, Barabsi-Albert (BA) model, power distribution