Abstract：In order to select proper concentration of hydrogen sulfide（H2S）suitable for root regeneration and growth of double-root-cutting grafted tomato seedling，this paper took‘Jinzuan’as rootstock and ‘Fendujinguanwang’as scion；and studied the effects of different concentrations of NaHS（0.1，0.2，0.3，0.4，0.5 mmol · L-1，donor of H2S）solutions on growth and root system morphology of tomato double-rootcutting grafted rootstocks and seedlings．The results showed that seedlings treated with 0.2 mmol · L-1 NaHS all reached the maximum value in plant height，stem diameter，leaf area，dry and fresh single plant weight and regenerative root activity of root-cutting rootstocks；and also significantly increased the endogenous H2S content，activity of D-cysteine desulfhydrase（DCD）of rootstock．Meanwhile，0.2 mmol · L-1 NaHS could notably promote the growth and root system development of double-root-broken tomato grafted seedlings．
