This paper aims to study seed germination and seedling emergence of three dominant species (Caragana korshinskii Kom, Medicago sativa Linn and Elymus dahuricus Turcz) in Mu Us sandy land under different water supply regimes and sand burial depths. The results indicate that: 1) For C. korshinskii and M. sativa, a relative large number of seeds emerge mostly at 2.5 -5.0 mm water supply. The maximum seedling emergence rate of C. korshinskii is 59.00% ±7.21%, while that of M. sativa is no more than 40%. The seedling mortality of M. sativa is relatively high at 2.5 mm water supply, which means the death of a lot of seeds after germination. 2) For E. dahuricus, seeds emerge well at 5.0 -9.0 mm water supply. The maximum seedling emergence rate of E. dahuricus is 52.67% ±10.67%. 3) The most suitable sand burial depths for the seeds of C. korshinskii and M. sativa are 0.5 -1 cm and 0.5 cm. As the burial depth increases, the seedling emergence rate of two species, C. korshinskii and M. sativa, decreases significantly. C. korshinskii has the highest rate of non-emergence at 4.5 cm burial depth. 4) E. dahuricus adapts well to sand burial, and has the maximum seedling emergence rate at 4.5 cm burial depth.