This paper describes a LAN construction support system using VMware for network administration study. It has designed and developed to help instructors to modify and maintain the LAN easily and quickly to meet learners’ requirements. We have been proposed a teaching method to realize a hands-on laboratory for teaching administrative aspects of computer networking. However, it was time consuming job to customize and maintain the laboratory LAN corresponding to learners’ requirements. The support system overcomes this problem to automate configuration process of customized LAN from its configuration data. In this paper, we explain the background of LAN administration study using VMware, and mechanism of the LAN construction support system and its evaluation.