OBJECTIVE In order to provide a scientific water management for the standardized cultivation, the effects of soil water content on the seedlings growth and active ingredients of S. miltiorrhiza were studied. METHOD A water stress experiment with pot culture was applied to study the effects of different soil water content on the seedlings growth, biomass and the accumulation of tanshinone, salvianolic acid B and mineral nutrition of S. miltiorrhiza. RESULT Soil water content had serious influence on the growth, yield, outer appearance and inner quality of S. miltiorrhiza when the soil was under severe drought or with too much water. But the shoot and root biomass of S. miltiorrhiza was increased significantly under mild drought. As well as the content and cumulant of dihydrotanshinone I , cryptotanshinone, tanshinone I , tanshinone IIA and salvianolic acid B in root of mild drought were increased. It also enhanced the P, K, Ca, Mg, Mn, Zn, Cu and Fe contents of S. miltiorrhiza under mild drought. CONCLUSION The overall results from the experiment suggest that the appropriate soil water content is 55% to 60% in seedling stage of S. miltiorrhiza. And it will be strongly recommended that the ridge culture and suitable soil moisture management must be carry out in production of S. miltiorrhiza in order to improve the yield and quality of medicinal materials.