This paper dealt with the study and analysis of UV-Vis absorption spectra of treated fibers of Luffa cylindrica (LC), pure matrix and LC fiber-resorcinol composites. The effect of incorporation of LC fiber in to the matrix on the absorption peak is analyzed. The shifting of absorption peak is noticed when the alkali treated LC fibers are incorporated into the matrix. Shifting of the absorbance edge towards low wavelength region for alkali treated LC fiber composites indicate an increase in band gap. The increase in band gap results in decreased optical conductivity of the treated LC fiber composites. Also it is observed that the absorbance peak shifts towards the higher wavelength region with addition of more wt of LC fiber into the matrix. It indicates decrease of band gap and increase of optical conductivity with increase in wt of LC fiber in the composites.