In this paper, cysteamine/glucose grafted CdTe quantum dots (QDs) were synthesized and subsequently, the carbon chains wrapped around the surfaces were carbonized via further hydrothermal heat treatment to obtain raisin-bun-like carbon protected CdTe QD nanocomposites (CdTe@C NCs). As shown by Fourier-transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectrum (XPS) analysis and Raman spectroscopy, the carbon material was successfully capped around the surface of the CdTe QDs. The optical properties of the as-prepared products were carefully investigated by UV-Vis and photoluminescence (PL) spectroscopy techniques. With the protection of the carbon shell the as-synthesized CdTe@C NCs tolerate both acidic and alkaline environments, such as NaCl solutions as well as oxidative hydrogen peroxide. The MTT assay also confirmed the low cytotoxicity of CdTe@C NCs.