Recently, ultrafast, coherent X-ray science and technology has received a lot of attentions, especially with respect to tabletop X-rays produced by high harmonic generation (HHG). The femtosecond-to-attosecond X-ray pulse enables the dynamics of chemical reactions, nano-materials and bio-molecular systems to be studied with unprecedented temporal and spatial resolution. I will show you the history, working principle and potential applications of HHG and our recent research progress in NTHU - bright supercontinuum in the Mid-IR for one-cycle pulse generation and in the EUV for isolated attosecond pulse generation. Those timescale are remarkable in that it approaches a regime where electrons behaviours can be fully characterized. In addition, due to its short wavelength and great spatial coherence, HHG light is an excellent light source for seeing dynamics of nano-world.