I have been working for the development of supramolecular host-guest system, where the guest is transition metal complex and host is a hollow barrel shaped molecule. In this system, photophysical properties of transition metal complexes can be modified in various dimensions, which is highly potential to use in light harvesting technique, such as in designing sensor device, enhancing the efficiency of LED display, etc. The interaction process in between host and guest can mimic the biological process, therefore clear understanding of similar mechanism may help others to design new medication technique.