The effect of nozzle-lip thickness on supersonic jet noise generated from Laval nozzle with a design Mach number 2.0 was experimentally investigated using acoustic measurement and flow visualization. Experiments were carried out over a wide range of the nozzle pressure ratio from 2.0 to 18.0. The obtained results show that the nozzle-lip thickness significantly influences the acoustic characteristics of supersonic jet noise, such as jet oscillation mode, screech tone intensity and overall sound pressure level.