Recent advances in single-molecule fluorescence microscope techniques have allowed singlemolecule sensitivity to probe various protein-DNA interactions, their structural changes, and fundamental cellular processes in a living cell. In this talk, I will introduce a novel single-molecule fluorescence microscope technique and single-particle tracking method based on super-resolution imaging, which were used for investigating cellular dynamics in living cells. Transcription, a process of mRNA generation by RNA polymerase (RNAP), is highly coupled with translation by ribosome in bacteria. The effect of the transcription-translation coupling on the transcriptional dynamics and the localization of genes in a living cell is poorly understood. Here, we directly observe the dynamics of transcription and the movement of the subcellular localization of genes actively transcribed by RNAP in living cells at the sub-diffraction limit resolution. The subcellular localizations of the nonmembrane protein’ genes, actively transcribed by RNAPs, move toward outside nucleoid or to plasma membrane by the effect of translation by ribosome. The movement of genes by transcription-translation coupling is general for both E. coli RNAP and T7 RNAP. Our observation demonstrates how two spatially separated processes of transcription and translation are coupled in bacteria and the movement of genes by the cooperation between transcription and translation plays a crucial role in the effective expression of genes in living cells. This work paves the way to observe individual protein machinery and to reveal fundamental cellular processes in living cells. In the second part, I will introduce real-time single-protein tracking in a living cell, which was used to study the interactions of membrane proteins. Finally, I will introduce new single-molecule FRET technique for observing millisecond conformational change of biomolecules.