For Parallel Computing Java Remote Method Invocation (RMI) provides a high performance flexible type of procedure. In current Java usage, RMI system is not very much efficient for communication. In this paper we have presented Distributed Parallel Computing using efficient multithreading algorithm and RMI system within 8 hosts. The hosts will carry out Prime number calculations that will also show how many prime numbers are there in the given number (user input). In single host this calculation will take much time & instructions are executed one after another. We have aimed at distributing the task among multiple hosts where the task will execute concurrently. For concurrency we have used multithreading. The results also show that the proposed system’s performance increases when we use more highly configured PC.