Abstract: A sample, facile, liquid phase reduction approach is developed for the synthesis of Cu₂O. In this experiment, the size and morphology of Cu₂O could be precisely tuned by readily changing the conditions of reaction kinetics, such as temperature and surfactant. Specially, cubic and octahedral Cu₂O are successfully synthesized, respectively, together with tunable particle size in the ranged of 100 nm to 650 nm. It is found that the color of Cu₂O could be altered by fine-tuning the size and morphology, due to the obvious change in absorption of light and carriers transport characteristics based on the experimental observation and characterization. The experiment establishes the relationship among synthetic parameters, microstructures, and optical properties, and it could be easily extended to innovative and comprehensive experimental teaching used for the undergraduates because of its safe and green synthesis approach, straight-forward and observable experimental phenomenon, and easy to operate. It would greatly help students understand advanced scientific issues, stimulate their interest in learning, and resolve the practical difficulties in terms of learnt knowledge.