A networked structural laboratories system for seismic simulation of structures is presented. It consists of an independent network based communication platform (NCP) and various applications based on NCP. The NCP was developed based on client/server concept along with a proposed data model and communication protocols. It is capable of transferring control and feedback data among computers connected by Internet that is a hierarchical network with ubiquitous deployment of middleboxes, such as firewalls and network address translators. Communication speed tests were conducted in various network environments. Applications for hybrid dynamic test of bridge and building structures have been developed and remote hybrid tests of structures were carried out among the Hunan University, the Harbin Institute of Technology, and the Tsinghua University.