One of basic and important treatments for cancer patients has been chemotherapy, but this treatment method has been limited by the lack of specificity of drugs towards cancer cells, which has led to increased contraindications and unwanted and side effects in healthy cells of the human body. Therefore, finding drug nanosystems for targeted cancer treatment and cure has been of great and surprising importance.In this project, potential of functionalized single-walled carbon nanotubes as a nanosystem for drug delivery of dacarbazine was investigated. As a result, main candidate was the COOH functional group for single-walled carbon nanotubes for drug delivery in aqueous media, and the possibility of binding interaction of dacarbazine with SWCNT-COOH was investigated.Optimization of interaction and complex components of this interaction in the gas phase and thermodynamic calculations were performed using the B3LYP/6-311+G* density functional method, which showed that structure of the complex nanosystem d is more stable and the process is spontaneous and exothermic.Also, according to the results, the intermolecular interaction of dacarbazine with SWCNT-COOH is of the hydrogen bond type and the charge transfer is from SWCNT-COOH to dacarbazine.In Monte Carlo calculations, the total interaction energy of the complex nanosystem increased to -17.926 and 〖∆G〗_sol〗 had a numerical value of -115.02 kcal/mol.Therefore, this nanocarrier has been used for drug synthesis, transport, and release, but there are still many questions about this nanocarrier in medicine. It is hoped that this problem will be solved in the coming years and can be a path to targeted cancer treatment.