MANET environment was represented by a combination of node position, mobility speed, node type, and number of nodes. In this paper, a novel system for MANET environment evaluation is proposed by involving fuzzy multi-criteria decision maker (FMCDM) to reflect the importance of the MANET environment on the overall protocols performance. The proposed system combined with another system that previously suggested for MANET protocol evaluation. the outputs of these systems are merged to produce one single crisp value in interval [0 1]. Then, a case study for an office is implemented using OPNET 14.5 simulator to test the proposed system. results proved that MANET environment could be used to enhance the QoS of the protocol. in another world, factors along with inherent characteristics of Ad-hoc networks may result in unpredictable variations in the overall network performance.