Cell-free system is interesting and useful for studying nuclear assembly in mitosis. Atomic force micro- scopy (AFM), which is a simple way for imaging fixed reas-semble nuclei with high resolution, has not been used in the cell-free system. In this paper, we put forward an air-drying sample preparation for AFM. Using AFM, we observed nu-clear reassembly process within 100 nm resolution in a cell-free system. As a result, we found that the images were artifact-free, and with higher resolution compared with fluo-rescent optical microscope images. Furthermore, the mor-phology of membrane vesicles was obtained clearly, and a dynamic change of morphology during the vesicles?ap-proaching to nuclear envelope was also observed, which is enlightened to understand the mechanism of nuclear enve-lope assembly. Cell-free system is interesting and useful for studying nuclear assembly in mitosis. Atomic force micro-scopy (AFM), which is a simple way for imaging fixed reas-semblenuclei with high resolution, has not been used in the cell-free system In this paper, we put forward an air-drying sample preparation for AFM. Using AFM, we observed nu-clear reassembly process within 100 nm resolution in a cell-free system. As a result, we found that the images were artifact- free, and with higher resolution compared with fluo-rescent optical microscope images. which, mor-phology of membrane vesicles was obtained clearly, and a dynamic change of morphology during the vesicles? ap-proaching to nuclear envelope was also observed, which is enlightened to understand the mechanism of nuclear enve-lope assembly.