Abstract: The synthesis process of poly(N-isopropylmethacrylamide)@poly(N-isopropylacrylamide) (PNIPMAM@PNIPAM) hollow microgels has been studied. Using the morphological characterization method combined with scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the particle size, three-dimensional and internal ultrastructure of core-shell microgels in a simple and intuitive way can be obtained. Furthermore, the morphological characteristics of the synthesis process of PNIPMAM@PNIPAM hollow concentric double-shell microgels were revealed.