Multi-cluster with NAT (Network Address Translation) mechanism is a kind of building cluster of clusters (CoCs) in parallel processing, we can easily combine two or more PC clusters which had setting on difference place to form a big one parallel system to reach the acceptable performance and resolving the issue of insufficient public IP address. In this paper, it includes three parts: First, we construct a CoCs with four Linux PC clusters which connected with NAT on difference places in a LAN environment. Second, we build a monitor system in our system to monitor and observe this system in a convenient way; this monitor system also has a client with mobile availability for users by using mobile devices. Third, we evaluate the system performance with different MPI parallel programs for the analysis of different parallel models.