Snow-cover changes in temperate desert ecosystems influence plant diversity, richness and distribution. The growth and distribution of herbaceous plants in these ecosystems are closely related to snow-cover depth, the most important water resource during the growth period due to water shortage during the dry season. However, the response to snow-cover change in winter remains unclear. The present investigation was undertaken to examine the influence of snow-cover change on the root growth of herbaceous species. The growth of desert typical ephemeral species, Erodium oxyrhinchum, was examined in Gurbantunggut Desert with four snow-cover depth treatments in winter. The four treatments were snow removal (-S), ambient snow, double snow (+S) and triple snow (+2S). The snow depth addition increased the abundance and growth rate of herbaceous plants. It also enhanced the biomass (including total and individual biomass) of these plants. The leaf area of E. oxyrhinchum increased significantly with snow addition, and the leaf dry matter content had an opposite trend. The study showed that the aboveground section of the plant was more sensitive to snow change than the underground. Snow change also influenced the root morphology. Snow removal resulted in the emergence of more lateral roots, whereas snow addition promoted the elongation of the main root for water and nutrient absorption. These results explain how changes in winter snow-cover depth alter plant growth, community structure and ecosystem function during the growing period in temperate desert ecosystems.