Our lab has successfully synthesized microcapsules using interfacial polymerization technique. The core material and the wall of these microcapsules have been illustrated to be crystal violet lactone and polyurea, respectively, by both infrared and ultraviolet spectra. To make unique microcapsules, the presence of ethylene diamine in toluene diisocyanate system is important. Use of methyl cellulose with longer ethylene oxide chain length of nonylphenyl polyoxyethylene ether in a toluene diisocyanate system containing ethylene diamine will form small particles of polyurea microcapsules. Furthermore, in the presence of a fixed amount of sodium lauryl benzene sulfonate as an emulsifier, sodium carboxy methyl cellulose is better than methyl cellulose for use in making polyurea microcapsules in terms of their particle sizes. © 1993 John Wiley & Sons, Inc.