The influence of the kind of alkali (KOH, NH4OH, ethanolamine) in alkali treatment on the formation of multihollow structure within submicron-sized styrene-methacrylic acid copolymer particles by the alkali/cooling method proposed by the authors was examined. The original particles were produced by emulsion copolymerization. The obtained results indicate that there was no great difference in the preparation of the multihollow particles by the method using the three kinds of alkali and support the formation mechanism of multihollow structure proposed previously.