A review. This article discusses the potential of self-modeling curve resoln. anal. (SMCR) for the evolution of online vibrational spectral data of polymn. and transesterification. After the general introduction of the SMCR approach, representative SMCR techniques like orthogonal projection anal. (OPA) and simple-to-use interactive self-modeling mixt. anal. (SIMPLISMA) are briefly outlined. As examples the SMCR anal. of the Raman spectra of the block copolymn. of styrene and 1,3-butadiene and that of the near-IR (NIR) spectra of the melt-extrusion transesterification of ethylene-vinyl acetate copolymer will be illustrated. In the last part of this review paper, a new powerful SMCR method that we have recently proposed is demonstrated.