On the basis of investigating the statistical data of bus transport networks of three big cities in China,wepropose that each bus route is a clique(maximal complete subgraph)and a bus transport network(BTN)consists of alot of cliques,which intensively connect and overlap with each other.We study the network properties,which includethe degree distribution,multiple edges’ overlapping time distribution,distribution of the overlap size between any twooverlapping cliques,distribution of the number of cliques that a node belongs to.Naturally,the cliques also constitute anetwork,with the overlapping nodes being their multiple links.We also research its network properties such as degreedistribution,clustering,average path length,and so on.We propose that a BTN has the properties of random cliqueincrement and random overlapping clique,at the same time,a BTN is a small-world network with highly clique-clusteredand highly clique-overlapped.Finally,we introduce a BTN evolution model,whose simulation results agree well withthe statistical laws that emerge in real BTNs. On the basis of investigating the statistical data of bus transport networks of three big cities in China, wepropose that each bus route is a clique (maximal complete subgraph) and a bus transport network (BTN) consists of alot of cliques, which intensively connect and overlap with each other. We study the network properties, which include the degree distribution, multiple edges’ overlapping time distribution, distribution of the overlap size between any two overlapping cliques, distribution of the number of cliques that a node belongs to. Naturally, the cliques also constitute anetwork, with the overlapping nodes being their multiple links.We also research its network properties such as degreedistribution, clustering, average path length, and so on .We propose that a BTN has the properties of random cliqueincrement and random overlapping clique, at the same time, a BTN is a small-world network with highly clique-clustered and highly clique-overlapped. Finally, we introduce a BTN evolution model, whose simulati on results agree well with the statistical laws that emerge in real BTNs.