Abstract: Monodispersed oil-in-water (O/W) emulsions containing monomer terephthaloyl dichloride (TDC) were prepared by Shirasu-porous-glass (SPG) membrane emulsification method, and the factors influencing the emulsification process were experimentally investigated. The results showed that to prepared monodisperse O/W emulsions by SPG membrane emulsification, it was more important to choose an anionic surfactant than to consider hydrophile-lipophile balance (HLB) matching. Both the monodispersity and stability of emulsions could be improved by increasing the viscosity of disperse phase or continuous phase. With increasing monomer concentration inside the disperse phase, the monodispersity of emulsions became slightly worse and the mean diameter of emulsions gradually became smaller. Monodisperse monomer-containing emulsions were obtained when the SPG membrane pore size was larger than 1.0 μm; however, when the SPG membrane pore size was smaller than 1.0 μm, no monodisperse emulsions were obtained because of the formation and chokage of p-phthalic acid (TPA) crystals in the pores of the SPG membrane. With increasing emulsification time, the average emulsion diameter generally decreased, and the monodispersity of emulsions gradually became worse.