There is provided a set of methods for generating state space models of general VLSI interconnect and transmission lines, trees and nets by closed forms with exact accuracy and low computation complexity. The state space model is built by three types of models: the branch model, the connection model and the non-connection model, that are block matrices in closed forms, arranged with topology. The main features are the topology structure, simplicity and accuracy of the closed forms of the state space models {A,B,C,D} or {A,B,C}, computation complexity of O(N) in sense of scalar multiplication times, where N is the total system order, practice of the modeling, ELO model simplification, and their optimization. For evenly distributed interconnect and transmission lines, trees and nets, the closed forms of state space model have the computation complexity of O(1), i.e., only a fixed constant of scalar multiplication times.