We propose a natural model of evolving weighted networks in which new links are not necessarily connected to new nodes. The model allows a newly added link to connect directly two nodes already present in the network. This is plausible in modeling many real-world networks. Such a link is called an inner link, while a link connected to a new node is called an outer link. In view of interrelations between inner and outer links, we investigate power-laws for the strength, degree and weight distributions of weighted complex networks. This model enables us to predict some features of weighted networks such as the worldwide airport network and the scientific collaboration network.