The objectives of this study were to explore the effects of different environmental conditions on seedling root growth and to provide important guidelines for forest regeneration and sustainable management. Thus, morphological characteristics of seedling roots of Quercus liaotungensis were investigated. The concentrated distribution zone of Q. liaotungensis in Shaanxi Province is located in the Loess Plateau and the north slope of the Qinling Moutains. The study was conducted in three distribution areas of Q. liaotungensis, which including the north slope of the Qinling Moutains (Taibai), southern Loess Plateau (Huanglong), and central Loess Plateau (Yan'an). Root morphological indices of 1-5-year-old Q. liaotungensis seedlings were investigated and the influences of environmental factors on root growth were analyzed. The results showed that root morphological indices were significantly different between trees grown in southern and northern areas. During the early growth stages of the seedlings (1-2 years), root morphological indices were constrained. The total root length, surface area, volume, root tips, averaged diameter, tissue density, and biomass per seedling increased and then decreased from the north slope of the Qinling Moutains to the central Loess Plateau, while the largest indices were documented in Huanglong. As a result, the roots of Q. liaotungensis seedlings in Taibai by improving root forks and decreasing the total surface area, volume, and average diameter to adapted to the environment. The roots of Q. liaotungensis seedlings in Huanglong and Yan'an by improving the elongation, specifically increasing the total surface area, volume, and average diameter, as well as by reducing root forks to adapted to the arid environment. Relationships between seedling root system indices (including the total root length, surface area, volume, root tips, and forks per seedling) and seedling age were best described by a linear function (y=ax + b, a > 0, P < 0.05). Redundancy discriminate analysis revealed that root forks, total root length, specific root length, and root tips of Q. liaotungensis seedlings were significantly positively correlated with available phosphorous, nitrate nitrogen, available potassium, annual precipitation, gravel content, and available nitrogen, whereas they were significantly negatively correlated with soil pH, mean annual temperature, and mean summer temperature. We conclude that appropriate gravel content and moisture are favorable for the growth of Q. liaotungensis seedling roots.