The emulsion polymerization of lauryl methacrylate and its copolymerization with trimethylolpropane trimethacrylate (TMPTMA) were investigated. The induction period (IP) for LMA polymerization was observed to be very long as compared to substantially no IP for methyl methacrylate polymerization. The addition of TMPTMA as a crosslinker clearly prolonged IF, owing to the reduced radical entry of oligomeric growing radical having rather hydrophilic and crosslinkable TMPTMA units into the polymer particle surface. Besides, no gelation was observed even above 90% conversion for LMA/TMPTMA(80/20) copolymerization. The initial abrupt increase in the conversion dependencies of weight-average molecular weight results from the compartmentalization of reaction loci and the gel effect.