The development, properties and some researches of scale-free networks were summarized.  Some complex network characteristics of global shipping lines network were empirically analyzed.  Ports and shipping services were equated to dominant products and their complementary products in product networks.  The mechanism of network effect in the production system was analyzed by using two-stage budgeting procedure.  It is seen that some complex network characters in a certain domain come from the influence of network benefits in the production network.