One of the major challenges in cell physiology is revealing the molecular mechanism underlying cell functions. This paper reviews applications of near field optics and quantum dots to the cell biology. In the first part (1) imaging of single ion channels with near field illumination and in the following part (2) the process of stress fiber formation examined with quantum dots are introduced.(1) The mechanosensitive channel of large conductance (Msc L) has been examined to explore the molecular basis of the channel gating. We have developed a noble experimental setup; the Msc L is imaged with fluorescent molecular probes for FRET pair, and observed by total internal reflection microscopy.(2) The stress fiber is a long linear structure and orients along the long axis of a cell. We have examined the process of stress fiber formation by employing digitoninpermeabilized semi-intact cells and quantum dots (Qdots).