Thiosalicylic acid (TSA) was used as a stabilizer to synthesize CdTe quantum dots (QDs) in aqueous solution. The reaction conditions, such as refluxing time, precursor concentrations, the molar ratio of reactants, and the pH value, were investigated. Under optimized conditions, the photoluminescence quantum yields (PLQY) of TSA-capped CdTe QDs were up to 15%. The morphology and composition of CdTe QDs were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Theoretical calculations show that TSA increases electronic coupling through the conjugated π bond structure, thus the TSA-capped CdTe QDs are expected to be applicable in solar cells.