Ring-opening polymerization(ROP)of octamethylcyclotetrasiloxane(D4)at 80℃ to form microemulsion was introduced. Cationic emulsifier, octadearyl dimethyl ammonium chloride(OTAC)and nonionic emulsifier,iso-tridecanol ethoxylate(1307)were blended as composite emulsifier; potassium hydroxide(KOH)was used as catalyst. The effect of dosage of cationic emulsifier, dosage of nonionic emulsifier, mass ratio between cationic and nonionic emulsifier and the total amountof composite emulsifieron particle size,particle ...