With the three kind of two-year-old Liquidambar seedlings: Liquidambar formosana, Liquidambar acalycina and Liquidambar styraciflua as study object, studying the influence of natural drought on conformation and functional characteristics of Liquidambar seedling root system, by using a randomized complete block experiment. The results showed that except the carbon content, the difference of all indexes in all treatments (including seed and drought treatment) was significant (P < 0.01) under the drought stress, the relative growth rates of specific root length, specific surface area and root bifurcate of the Liquidambar acalycina were the highest, which reached to 56%, 30% and -4% respectively; which of Liquidambar styraciflua were the lowest, reached to 9%, -3% and -19% respectively. While the relative growth rates of Liquidambar styraciflua root density and roots average diameter were the highest, which reached to 40% and -10% respectively, which of Liquidambar acalycina were the lowest, reached to -27% and -16% respectively. The relative growth rate of the Liquidambar styraciflua root system nitrogen content was the highest, which reached to 127%, which of Liquidambar formosana was the lowest, reached to 41%. The relative growth rate of Liquidambar formosana C/N was the highest, which reached to -26%, which of Liquidambar styraciflua was the lowest, reached to -56%. The results also indicated that the rootlet at 0 Liquidambar styraciflua> Liquidambar acalycina.