To produce safe, stable, and cost-effective quantum dots (QDs), the experiments were conducted with paraffin liquid as a solvent. CdSe QDs are synthesized by using a pyrolysis based on the chemical colloidal method. When the cadmium precursor was prepared, the tuning of stearic acid concentrations was implemented. The investigations of crystallographic, morphological, optical properties tell that the CdSe QDs with smaller amount of impurities, smaller particles in size and larger energy gap are synthesized at relatively low stearic acid concentration, implying that the stearic acid concentration is a crucial parameter in controlling the size of QDs.