The effects of hydrogen on the optical properties of lead zirconate titanate (PZT) ceramics and BaTiO3 single crystals have been investigated. The experimental results showed that the color of BaTiO3 single crystals changed from light to dark after charging of hydrogen in NaOH solution at room temperature and in H-2 gas at high temperature, and then, restored to light color after outgassing in the air, which were the same as PZT-5H ceramics reported earlier. Measurement of the absorbance indicated that hydrogen increased the absorbance within the visible spectrum for both PZT ceramics and BaTiO3 single crystals. The first principles calculations for Pb(Zr0.5Ti0.5)O-3 and BaTiO3 showed that hydrogen increased the absorbance within the infrared and visible spectral region and the absorbance increased with the rise of hydrogen concentration. Density of states (DOS) researches indicated that hydrogen changed the DOS of the outer shell electrons, which caused the change of absorbance spectrum.