In this thesis UV/Vis absorption spectra of caffeine in water and dichloromethane, copperrnsulphate, and mixture of caffeine and copper sulphate in water solution is investigated.rnUV/Vis absorption spectrum of Cu (II)-Caffeine complex is also investigated as arnfunction of time during refluxing to check complex formation. The molar decadicrnabsorption coefficient of caffeine is calculated. Fluorescence emission spectra of Cu (II)-rnCaffeine complex is also investigated and compared with its absorption band. Arearnnormalization analysis method is used. Finally, a better derivative fluorescence methodrnfor determination of caffeine content of substances is recommendedrnKey words: Absorbance, Molar decadic absorption coefficient, Reflux, Complexrnformation, Derivative Fluorescence, Is-emission point, Area normalization