【Objective】Investigating the intra- and inter-specific competition traits of Sinomanglietia glauca saplings can provide scientific basis for the targeted protection of this endangered plant. 【Methods】We investigated regeneration layers of S. glauca community and used the Hegyi competition model to assess the intra- and inter-specific competition intensity of 186 S. glauca saplings in Yujingshan Provincial Nature Reserve, Jiangxi Province.【Results】We found that intra-specific competition was dominant in the S. glauca saplings competitive pressure. Intra-specific competition index (CI) was 1390.66 and accounted for 61.55% of total CI; the relationships between the diameter at breast height (DBH) and the intra-, inter-specific, and total CI of S. glauca saplings were all exponential functions, which indicated these three competition intensities gradually decreased with increasing of DBH. In addition, S. glauca saplings had higher inter-specific competition intensity than did intra-specific competition intensity before the DBH was 2.80 cm, and then showed an opposite trend.【Conclusion】During the growth process of S. glauca saplings, inter-specific competition generally was the primary source of competition; intra- and inter-specific competition would gradually weaken; the proportion of intra-specific competition to the total competition intensity would gradually increase. In order to alleviate the competition pressure S. glauca saplings, the competitive non-endangered species should be appropriately removed in the regeneration layer of the S. glauca natural community.