Abstract: The study included 67 families from 6 provenances, collected from key Cinnamomum cassia-producing regions in Nanning, Cenxi, Rongxian, Pingnan, and Dongxing in Guangxi, as well as Xinyi in Guangdong. A comparative analysis of seedling height and ground diameter growth traits during the seedling stage was conducted. The Bulgin multi-trait comprehensive evaluation method was employed to assess this stage. Growth differences among C. cassia families from various provenances were examined, and the excellent provenances and families were screened out. The findings indicated that differences in seedling height and diameter among different provenances and families were significant. The Cenxi provenance grew best, while the Pingnan and Dongxing provenances grew poorly. The potential for seed source selection was relatively large because the heritability of seedling height and diameter at breast height is greater than 0.9 and there is significant variation among different seed sources. 13 superior families with obvious growth advantages were preliminarily selected based on the estimation results of family seedling height, ground diameter and their herit. The average seedling height was 29.05 cm, and the average ground diameter was 4.42 mm, which were 1.31 times and 1.10 times of the population average, respectively. The average genetic gain of seedling height and ground diameter reached 29.41% and 9.12%, respectively. The best of them is the 37th family of the Cenxi provenance, followed by the 17th family of the Nannin provenance. The selected family line was ranked as 37^th > 17^th > 39^th > 38^th > 24^th > 19^th > 32^nd >36^th > 10^th > 16^th > 13^th > 64^th > 23^rd through comprehensive evaluation. The correlation analysis showed that the correlation coefficient between seedling height and ground diameter is 0.750, reaching an extremely significant correlation, ground diameter was significantly negatively correlated with latitude, both seedling height and ground diameter were significantly negatively correlated with annual rainfall.