Abstract　 　　
　Exoplanet science is one of the most rapid-advancing frontiers in present Astronomy. We are now entering an exciting era in which we can not only do statistics on planet populations, but also perform detailed characterization on the atmospheric properties. By diagnosing the spectra obtained through transits and secondary eclipses, atmospheric energy budget, temperature structures, chemical compositions and abundances could be investigated and linked to planet formation and evolution history. In this talk, I will present our efforts in characterizing hot-Jupiter atmospheres using the ground-based facilities based on photometric and spectroscopic techniques. Using the GROND imaging instrument on the MPG/ESO 2.2m telescope, we carried out a project observing secondary eclipses of hot Jupiters. We aim at detecting thermal emissions from dayside atmosphere and constraining the energy budget as well as temperature structure of deep atmosphere. We also started another project to reveal the chemical compositions of hot-Jupiter atmospheres through transmission spectroscopy using the DBSP and COSMIC spectrographs on the Palomar/Hale telescope. I will show the results and progress of these two projects.