Over‐expression of miR21 plays an important role in several cancers by promoting cancer cell proliferation, migration, invasion, and metastasis. Here, we attempted to prepare a beta cyclodextrin‐polyethyleneimine‐graphene quantum dot (βCD‐PEI‐GQD) nanocarrier for cellular delivery of miR21a. For this purpose, tosylated‐βCD and GQD were conjugated to branched PEI. The product was characterized by FTIR, 1H‐NMR, and fluorescence spectroscopy. The morphology, particle size distribution, and ζ‐potential of miR21a were examined by TEM and DLS following overnight incubation with βCD‐PEI‐GQD in aqueous media. The miR21 silencing was measured by stem‐loop RT‐PCR in HepG2 human hepatoma cell line. Cellular uptake and cell toxicity assays were determined by fluorescence microscopy and Trypan blue staining method, respectively. The formation of miR21a/CD‐PEI‐GQD Nanoplex with a decreased average size of 114 nm and a ζ‐potential (+36.1 mV) lower than CD‐PEI‐GQD nanocarrier by adding miR21a was confirmed at optimum C/P ratio =8.7. RT‐PCR revealed that miR21a/βCD‐PEI‐GQD Nanoplex significantly downregulated miR21 expression levels effectively. Overall, miR21a delivery using CD‐PEI‐GQD is presented as a novel trackable nanocarrier for cancer therapy.