The dependence of the lamellar growth kinetics on the molecular weight (MW) of poly(bisphenol A octane ether) (BA-C8) in the low crystallization temperature region was investigated using atomic force microscopy (AFM). We found that Lauritzen-Hoffman's theory can be used to analyze kinetics data of BA-C8 samples obtained in regimes I and II but not regime III. A new expression of lamellar growth kinetics was proposed on the basis of a simple kinetic model with a rough surface.