Multi Effect Desalination with Thermal Vapor Compression (MED-TVC) is one of the most effective desalination methods. It plays a vital role in the production of fresh water in many regions of the world especially in the Arabian countries. Parallel feed MED-TVC system has been modeled mathematically based on the first and second laws of Thermodynamics. A computer program has been developed using MATLAB program to simulate the system. A comparison between the program results and the data of actual plants has been conducted to verify the program's validity. The deviation between Model results and actual data has been found to be very small. The main design parameters that greatly influence the performance of MED-TVC plant have been identified. A parametric study has been carried out to investigate the effect of these parameters on the gain Ratio (GR), specific heat transfer area (SHTA) and specific total exergy destruction (STED). The obtained results indicated that the GR increases with increasing each of number of effects (NE), last effect temperature, salt concentration up to 2, and motive steam pressure. The SHTA increases with decreasing the top brine temperature (TBT) and/or motive steam pressure, while the SHTA decreases with increasing each of NE, the last effect temperature, and the salt concentration ratio. Moreover, the study has shown that STED increases with decreasing NE and/or TBT and increasing the motive steam pressure. The total and subsystems exergy losses of MED-TVC desalination system have been evaluated. The results show that the higher percentage of exergy destruction occurs in the ejector, which represents about 60% of the total exergy destruction. Meanwhile, the exergy destruction inside effects itself represents about 33% of the total exergy destruction in MED-TVC system.