Abstract: We report the recent progress in our studies of cell biology using micro-/nano-technology. Cells have a size of several to tens of microns, which makes them easily manipulated by micro-/nano-technology.The shape of the cell influences the alignment of the actin cytoskeleton, which bears the main forces of the cell,maintains the shape, and mediates a series of biochemical reactions. We invented a stretching device and studied the real-time actin filament dynamics under stretch. We found that one stretch cycle shortened the actin filaments and promoted their reassembly process.Cell migration is a complex mechanical process.We found that cell geometry determines the cell polarity and migration direction.We fabricated three-dimensional surfaces to mimic the topography in vivo,and further built a cell culture model by integrating the three-dimensional surface, microfluidics,cell patterning,and coculturing of multiple cell types. We also investigated the neuronal guidance by surface patterning.