High-redshift galaxies was thought to play a key role in understanding the early epoch of galaxy formation.Yet detecting and identifying galaxies at high redshifts were so inefficient until the Lyman Break techinque was invented in the 8m class telescope era.Now high-redshift galaxies were detected in multi-wavelength bands.Current studies of their stellar populations in these galaxies indicate that some of them were actually already old and became massive at high redshifts.This is a challenge to the current galaxy formation theory.In this talk,I will give a brief review on hunting high-redshift galaxies in the history of observational extragalactic astronomy.