α-mangostin is a natural product containing xanthone core structure isolated from mangosteen rind. It is known to possess many biological properties including antibacterial, antiviral, anti-inflammatory and antioxidant activities. Some food products such as XanGo Mangosteen Juice, Vemma Mangosteen Juice Nutrition Supplement and Nanoxan Gold containing α-mangostin are readily available in the market. Spectroscopic study showed that α-mangostin exhibits a maximum fluorescence peak at approximately 500 nm which can be utilized for internal irradiation and photoimaging purposes. It may also have an effect on a formulated products containing α-mangostin. However, the emission peak for α-mangostin was not observed in the PNIPAM microgel solution. In the present study, α-mangostin was added into PNIPAM microgel solution. The dispersion of α-mangostin was studied by using Dynamic Light Scattering (DLS) and Transmission Electron Microscope (TEM).