Hydrogen sulfide (H₂S) is an endogenous gaseous transmitter known to play an important role in biological functions. For the hepatic and intrahepatic targeting of H₂S prodrug at the cellular level, we developed two types of sulfo-albumins, in which five sulfide groups (source of H₂S) were covalently bound to succinylated (Suc) or galactosylated (Gal) bovine serum albumin (BSA). Sulfo-BSA-Suc and polyethylene glycol (PEG)-Sulfo-BSA-Gal, both released H₂S in the 5 mM glutathione solution, but not in the plasma. Sulfo-BSA-Suc and PEG-Sulfo-BSA-Gal were taken up by RAW264.7 cells (mouse macrophage-like cells) and Hep G2 cells (human hepatocellular carcinoma cells), respectively, and H₂S was released. These results indicate that Sulfo-BSA-Suc and PEG -Sulfo-BSA-Gal selectively released H₂S intracellularly. In a biodistribution study, up to 80% of ¹¹¹In-labeled Sulfo-BSA-Suc and PEG-Sulfo-BSA-Gal rapidly accumulated in the liver, 30 min after intravenous injection in mice. Furthermore, ¹¹¹In-labeled Sulfo-BSA-Suc and PEG-Sulfo-BSA-Gal predominantly accumulated in liver nonparenchymal (endothelial cells and Kupffer cells) and parenchymal cells (hepatocytes), respectively. These findings suggest that targeted delivery of H₂S prodrug to a specific type of liver cells was successfully achieved by bioconjugation.