Due to their special physical and chemical properties and potential applications from hydrogen storage to medical implantation, the carbon-based nanomaterials are in the frame of attention for many research groups all over the world. As synthesis techniques, we highlight arc discharge, chemical vapor deposition (CVD) and laser ablation. Even an expensive technique, laser ablation is suitable for single-wall carbon nanotubes (SWCNTs) synthesis, providing the highest yield of over 70%, while arc discharge yield is about 30% and CVD is about 42%. The most common investigation methods for carbon nanomaterials are micro-Raman spectroscopy, thermo-gravimetric analysis (TGA) and morphological and topographic studies done by atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HR-TEM). We also emphasize in this work that by involving a home-designed reactor, we successfully synthesized SWCNTs, carbon nano-onions (CNOs) as well as graphene in the same reactor. Tuning the experimental parameters, we switch the end type of nanomaterials. We have done comprehensive studies regarding the carbon nanomaterials synthesis.