Precipitation is the most important limiting factor for processes and functions of desert ecosystems and desert plant seedlings are extremely sensitive to precipitation changes during the growing season. In order to explore the response of desert plant seedlings to future precipitation pattern changes, two typical desert plant seedlings (Nitraria tangutorum and Artemisia ordosica) in Ulan Buh desert were selected as research objects. The artificial simulated precipitation addition experiment was conducted with five different gradients (CK: natural precipitation, A: +25% precipitation, B: +50% precipitation, C: +75% precipitation, D: +100% precipitation) based on the precipitation of growing season from June to September to study the growth of two plant seedlings and the response of root morphological characteristics to precipitation changes. The results showed that 1) different precipitation treatments had significant effects on the shoot growth of Nitraria tangutorum and Artemisia ordosica seedlings (P <0.05). The height, average crown, and base diameter of Nitraria tangutorum and Artemisia ordosica seedlings were significantly higher than the CK and increased with the amount of precipitation(except for the base diameter of Nitraria tangutorum).2) There were significant differences in total root length, total surface area, average diameter, total volume, number of root tips and number of branches between precipitation treatments(P <0.05). For the Nitraria tangutorum seedlings, the root parameters of B and C treatments were significantly greater than those of CK, A and D treatments, and there was no significant difference between B and C treatments (except for the average diameter); for the Artemisia ordosica seedlings, the total root length, total surface area, total volume, number of root tips and number of branches increased gradually with the increase of precipitation, while the average diameter increased first and then decreased, and reached the maximum under B treatment.3) Precipitation addition treatment significantly reduced the root-shoot ratio of Nitraria tangutorum seedlings, but had no effect on the seedlings of Artemisia ordosica, and the root-shoot ratio of Nitraria tangutorum seedlings was significant greater than the seedlings of Artemisia ordosica.4) The roots diameter of two seedlings were mainly distributed in 0-0.5mm and 0.5-1mm, and the ratio of fine root (<2mm) reached the maximum value under B and D treatment, respectively. It suggested that Nitraria tangutorum and Artemisia ordosica seedlings could adjust shoot growth and root morphology to adapt precipitation changes.