【Objective】 The efficiency of selection and long-term testing costs for clonal propagation candidates of Cunninghamia lanceolata were improved by implementing a short-term nursery test with 67 clonal propagation candidates. By analyzing the genetic variation of growth traits and the impact of genetic environmental interactions on the selection of various traits of clones during the seedling stage, this study explores strategies for ultra early selection of clone seedlings. 【Method】 A selection procedure was conducted from a population of two million seedlings, with 275 well performing individuals selected for further prorogation. The seeds were collected from a local third generation C. lanceolata seed orchard.The selected plants were propagated into clones by hedged cutting. Of the propagated clones, 67 individuals with a fine rooting ability were selected for further testing under a completely random block design with 12 plants per plot and 10 replications. Four traits (seedling height, diameter above ground, number of branches and the length of the longest branch) were measured after one year’s growth. Furthermore, a phenotypic analysis of variance model was constructed to estimate the values of genetic variance component and genetic environmental interaction effect variance component, and ASReml software was used to estimate in heritance and repeatability, respectively. 【Result】 After planting in the nursery for one year, the average seedling height, ground diamete, number of lateral branches and longest lateral branch length of the tested clones were 0.640 m, 1.010 cm, 10.30 and 0.28 m, respectively. The phenotypic variation coefficients of the four observed traits were 12.86%, 14.88%, 21.34% and 14.89%, respectively. There were notable genetic differences found in the traits of seedling height, diameter above ground, number of lateral branches, and length of the longest lateral branches among the tested clones, and the repeatability of the measured traits exceeded 0.74, and the estimated heritability remained stable at around 0.48. The variance component of the genetic and environmental interaction accounted for about 35% of the total genetic variance. There is a significant correlation between ground diameter and seedling height, number of lateral branches, and length of the longest lateral branch, with genetic correlation coefficients above 0.9. The genetic gain estimates of seedling height, number of lateral branches, and longest lateral branch length gradually increase with the decrease of selection rate based on the ground diameter trait. However, the variance ratios of repeatability, heritability, and genetic environmental interaction of seedling height, number of lateral branches, and longest lateral branch length remain within a relatively stable range, exhibiting varying degrees of wavy fluctuations. As the selection rate decreases, the value of repeatability and heritability of ground diameter decrease, while the variance ratio of genetic environmental interaction increases. When the selection rate decreased to below 40%, the genetic environmental interaction variance ratios of the three traits of seedling height, number of lateral branches, and longest lateral branch length of C. lanceolata clones reached 41.18%-48.61%, 37.82%-40.13% and 39.61%-54.37%, respectively. However, the genetic environmental interaction variance ratio of diameter rapidly increased from 45.91% to 94.33%.When the number of selected clones decreased from 19 to 16, the genetic environmental interaction variance ratios of ground diameter heritability and genetic environmental interaction variance ratios changed significantly, with diameter heritability decreasing from 0.226 3 to 0.091 4 and genetic environmental interaction variance ratios rapidly increasing from 63.09% to 83.26%. Based on a selection rate of approximately 30%, 19 clones were selected for further evaluation in multiple sites in a long-term afforestation project in a mountain area. The average seedling height, ground diameter, number of lateral branches, and longest lateral branch length of the selected clones were 0.73 m, 1.20 cm, 12.4 branches and 0.33 m, respectively. The estimated average genetic gains of the four observed traits were 10.81%, 15.45%, 16.66% and 13.88%, which were 14.06%, 18.81%, 20.39% and 17.86% higher than the population average, respectively. 【Conclusion】 The effect of genetic environmental interaction on the phenotypic traits of C. lanceolata clones cannot be ignored, and its interaction variance accounts for a large proportion of the total genetic variance. The growth of height and lateral branches of C. lanceolata clones are relatively less affected by the genetic environmental interaction effect, while the growth of ground diameter are more sensitive to changes in the microenvironment of the nursery or from unknown factors. Therefore, combining the growth performance of tree height and ground diameter of C. lanceolata clones for short-term testing can achieve ideal of selection. Reducing the selection rate does not eliminate the influence of genetic environmental interaction on ground diameter and longest lateral branch length. High intensity selection can actually increase the influence of genetic environmental interaction. Appropriate selection intensity can not only retain the richness of genetic variation in target traits between clones, but also fix most of the genetic environmental interaction effects. Short-term nursery testing can serve as a rapid preliminary screening technique, especially when there is a large amount of clonal candidates to be tested. Several benefits were apparent, including forest-land use and the long-term cost efficiency of testing. The clonal traits, genetic components, and interaction between genetics and environment could be evaluated in the super-early stage of clonal evaluation.