A dynamic resource allocation method for virtual resources in virtualized data centers has been proposed in this paper. Since resource allocation with constraint in virtual environment is NP-hard, the solution has been focused on approximate methods based on immune system mechanism using agent based model and Cooperative Coevolutionary Algorithm (CoCo-VM) that appears to perform well in finding a plausible answer [1]. The novelty of our approach lies in integrating an agent based greedy algorithm based on immune system functionality together with the cooperative co-evolutionary concept as an intelligent solution for virtual resource allocation in a large scale and distributed virtualized datacenters. Here, some mathematical analyses have been done to identify the parameters essential to assign a suggested allocation approach. Results of different evaluations in pure immune system (PIS)0F 1 and CoCo-VM methods demonstrate that, for the scenarios under consideration, the proposed resource allocation approach can significantly reduce resource consumption, increase number of successful services, and achieve higher performance.