Abstract: To deeply explore the intrinsic relationship between the phenotypic traits of Keteleeria seeds and the growth and development of seedlings, seeds were collected from five natural populations with a high number of superior Keteleeria trees.The phenotypic traits of the seeds and the growth of 100-day-old seedlings from different populations were measured, and correlation analysis was conducted.The results showed that there were extremely significant differences among populations in the thousand-seed weight, length, width, length-to-width ratio, perimeter, and cross-sectional area of the seeds.The thousand-seed weight and width of the seeds exhibited the following order: Xiqin population ＞ Laizhou population ＞ Mangdang population ＞ Tong'an population ＞ Zhanghu population.The seed length, perimeter, and area followed the order: Xiqin population ＞ Mangdang population ＞ Laizhou population ＞ Zhanghu population ＞ Tong'an population.However, the coefficient of variation for each seed trait among populations did not differ significantly.The growth of 100-day-old seedlings varied markedly among populations, with the Xiqin population showing the tallest seedling height（139.44 mm）and the largest ground diameter（1.50 mm）,significantly outperforming the other populations.Correlation analysis revealed that thousand-seed weight, length, width, perimeter, and area were all significantly positively correlated with seedling height and ground diameter growth.This indicates that in Keteleeria seedling cultivation, selecting seeds with larger size and heavier thousand-seed weight is beneficial for producing high-quality seedlings.