Using absorption spectrum method and Lambert-Beer law, the absorption coefficient of CdSe/ZnS (core/shell) quantum dots (QDs) doped in ultraviolet (UV) glue is measured with wavelength range of 450~850 nm and doping concentration of 0.073~0.367 mg·mL-1. An empirical formula of absorption coefficient related with the wavelength and doping concentration is presented. The refractive index of the QD doping UV gel as a function of wavelength is measured with different doping concentrations. An empirical formula of the refractive index related with the wavelength and doping concentration is obtained. The refractive index of pure QDs is also estimated and compared with that of bulk CdSe and ZnS. Based on the experimental results, the absorption coefficient is further related with the refractive index, and physical interpretation is discussed. The resonance frequency and damping constant of CdSe/ZnS QDs in a harmonic oscillator model are proposed by comparison of the absorption coefficient between the classical scattering theory and the experimental results.