N,N-dialkylaminoethyl methacrylate (DAEA) monomers are extensively used to prepare multi-responsive polymers. However, these monomers face high risk of hydrolysis in their ester groups when being polymerized in water-containing medias. Here, NMR spectroscopy was employed to continuously track the hydrolysis and solubility of four widely used DAEA monomers [CH2CH2R1COO(CH2)(2)N(R-2)(2); R-1=H or CH3; R-2=CH3, CH2CH3 or CH(CH3)(2)] under typical polymerization conditions. With this technique, the hydrolysis reactivity and absolute hydrolysis amount of these monomers are separately examined, and then their kinetic correlations with solubility, molecular structure, pH, and temperature are established, so that the hydrolysis of DAEA monomers and even other esters with similar cyclic structure can be predicted. The present efforts are expected to provide a general understanding for the hydrolysis of all the DAEA monomers, benefitting to the optimization of polymerization toward well-defined DAEA copolymers, as well as the design of smart soft matter for specific applications. (C) 2018 Wiley Periodicals, Inc.