DCell has been proposed as a server centric network structure for data centers. DCell can support millions of servers with high network capacity and provide good fault tolerance by only using commodity mini-switches. In this paper, we show that DCell is only a special case of a more generalized DCell structure. We give the generalized DCell construction rule and several new DCell structures. We analyze the graph properties, including the closed form of number of servers, bisection width, diameter, and symmetry, of the generalized DCell structure. Furthermore, we show that the new structures are more symmetric, have much smaller diameter, and provide much better load-balancing than the original DCell by using shortest-path routing. We demonstrate the load-balancing property of the new structures by analysis and extensive simulations.