Abstract: Based on the TRU system, the root system of Camellia szechuanensis Chien planted in Nanshan Botanic Garden, Longcha Huahai, and Yongchuan Road and Park Greenbelt was measured at 0.5 m and 1.0 m circle of the trunk, the number and distribution range of diameter ≥1cm roots were measured,in order to compare the distribution characteristics of roots under different site conditions, explore the limit factors of its application in road and park greenbelt. Meanwhile, 7 soil samples were collected, 8 indexes were measured for each soil sample, such as soil pH, EC and organic matter content and so on. The results showed that：（1） at a distance of 0.5 m to 1.0 m from trunk, the depth of diameter ≥1 cm root distribution is increasing, at a range of 0-62 cm; （2） at a distance of 0.5 m to 1.0 m from trunk, the number of diameter ≥1 cm roots increases gradually. Among them, The number of diameter ≥1 cm roots increased from 20 to 35 in Nanshan Botanic Garden, from 34 to 46 in Longcha Huahai, from 11 to 13 in Yongchuan district; （3）78%-85% of diameter ≥ 1 cm of roots distributed in 20-72 soil layer in Nanshan Botanic Garden, 80-82% of diameter ≥1 cm of roots distributed in 0-40 cm soil layer in Longcha Huahai, about 50% of diameter ≥1 cm roots distributed in 0-20 soil layer in Yongchuan district; （4） Compared with Nanshan Botanical Garden and Longcha Huahai, at a distant of 0.5 m and 1.0 m from trunk, the tree planted in Yongchuan district with the same diameter showed less root number, root distribution and root extension. This is closely related to the poor soil quality at the survey site. Anyway, improving the soil quality, especially the depth of main roots distribution, plays an important role in promoting the restoration of C. szechuanensis Chien growth.

Key words: Camellia szechuanensis Chien, root system distribution, TRU system