H2S, the newly discovered gasotransmitter, plays important roles in biological systems. However, the research on H2S has been hindered by the lack of controllable H2S donors that could mimic the slow and continuous H2S generation process in vivo. Herein we report a series of cysteine-activated H2S donors. Structural modifications of these molecules can regulate the rates of H2S generation. These compounds can be useful tools in H2S research.