Production of high-quality Multi-Walled Carbon Nano-Tubes (MWCNTs) is essential in some field, especially in medical and mechanical applications. This work illustrates the synthesis of high-quality (MWCNTs) by Injection Chemical Vapor Deposition (Inj-CVD) method using Ferrocene / Toluene solution as a carbon precursor and a catalyst. The effect of synthesis pyrolysis temperature, which has a pivot impact on the synthesis process, was investigated. The structure defects, impurities, thermal stability and sample morphology, as well as the mean diameters of the MWCNTs, were analyzed using Raman spectroscopy, thermal gravimetric analysis (TGA) and scanning electron microscope (SEM), respectively. The results revealed that a change in quality, mean diameter and purity were observed when the pyrolysis temperature varied between 700°C to 850°C. High-quality MWCNTs were observed by Raman spectroscopy at a pyrolysis temperature of 700°C with ID/IG = 0.2. While the outer and inner diameters were 25±6 nm and 7.8±1.5nm respectively, measured by Transmission Electron Microscope (TEM). The Inj-CVD shows an excellent control of the quality of the prepared MWCNTs by optimizing the synthesis temperature.