Abstract: To clarify the effects of hydrogen sulfide (H₂S) on seed germination and seedling growth of tobacco, the tobacco variety K326 was treated with different concentrations of H₂S by immersion to observe seed germination; the tobacco seedlings after normal germination were treated with different concentrations of H₂S, H₂S inhibitor (HA), H₂S scavenger (HT) and salt stress via hydroponics to observe their effects on the growth of tobacco seedlings. The results showed that compared with the control, the low concentration (0.05 mmol/L, 0.1 mmol/L) H₂S treatment promoted seed germination, while the high concentration (0.25 mmol/L, 0.5 mmol/L) H₂S treatment significantly inhibited seed germination. The HA treatment at 0.15 mmol/L and the treatment with HT at 0.2 mmol/L significantly inhibited the root length of seedlings. The treatment at 0.05 mmol/L H₂S promoted the growth of tobacco seedlings and alleviated the inhibition of salt stress on seedling growth and root development.