At the time of the development, standardization, and further improvement are vital to the modern cellular systems such as the next generation wireless communication (5G).Simulations are essential to test and optimize algorithms and procedures prior to their implementation process of the equipment manufactures. In order to evaluate system performance at different levels, accurate simulations of simple setups, as well as simulations of more complex systems via abstracted models are necessary. In this work, two new simulators for the sidelink Cooperative-Vehicle-to-Everything (C-V2X) communication have been implemented and carried out on both the physical layer (Link-Level (LL)) and network layer (System-Level (SL)). Detailed methodologies of the LL and SL simulators for C-V2X communication have been illustrated. In the LL simulator, we get the mapping curves of BLER and Signal-to-Noise-Ratio (SNR), which are used as a baseline for measuring the performance of the LL simulation. In addition, these mapping curves are used as the important Link-to-System (L2S) interfaces. The SL simulator is utilized for measuring the performance of cell networking and simulating large networks comprising of multiple eNBs and UEs. Finally, the simulation results of both simulators for C-V2X communication are presented, which shows that different objectives can be met by using LL or SL simulations types.Index Terms-5G, Sidelink, Link-level simulator, System-level simulator This communication is a point-to-multipoint communication where several Receivers (Rxs) try to receive the same data packets transmitted from a single Transmitter (Tx). As shown in Fig.1, a network-assisted DC-V2X transmission model is implemented in this work, using a highway scenario for data packets transmission, where all UEs are connected to Base Stations (BSs). What's moreover, the UE radio architecture consisting of the U-Plane and C-Plane is provided for C-V2X communication [6]. In this work, the Tx directly transmits its data packets to the surrounding Rxs in the communication range of the Tx in the U-Plane. This method of DC-V2X communication results in lower latencies, as it does not involve the C-Plane. And all UEs are connected to the operator network in the C-Plane where can provide network control for the DC-V2X communication [7]. In 3GPP, there are two sidelink transmission modes to assign radio resources to C-V2X Txs. They are as follows: