【Objective】The families’ growth performance and breeding value are evaluated through the Cryptomeria japonica seed orchard half-sib progeny test to clarify the genetic variation and the correlation laws of growth traits. Fast-growing, excellent families and individuals are selected for promotion and application. 【Method】 The growth traits data of 51 tested families were continuously collected by observing and surveying the seed orchard half-sib progeny test forests established at the Houping State Forest Farm of Fuding in Fujian Province in 2014. The individual and family heritability was estimated, and the growth performance of the tested families was evaluated by analyzing the genetic variation and correlation laws of growth traits based on data from one, three, five, six, and seven years of age. 【Result】The average height, diameter at breast height (DBH), crown width, and volume were 4.51 m, 6.68 cm, 2.09 m, and 0.011 10 m³, respectively. The variation coefficient of growth traits ranged from 16.75% to 101.60% at seventh years of age. The tested families demonstrated good adaptability and abundant variations in growth traits. Significant differences in height, DBH, and volume among families and repetitions across the one to seven year age range were observed. The growth performance of the forest was primarily influenced by the family genotype and site conditions. Family heritability of growth traits ranged from 0.465 to 0.649, while individual heritability ranges from 0.223 to 0.507. Growth performance was controlled by a moderate degree of genetic influence at the family level and a weaker degree at the individual level. The correlation coefficients among tree height, DBH, crown width, and volume ranged from 0.35 to 0.97 over one to seven years. Positive correlations among growth traits were highly significant. Eight fast-growing families were selected through the estimation of genetic gains and a comprehensive comparison. The average genetic gains of tree height, DBH and volume were 5.53%, 7.89% and 22.95%, respectively. In addition, 35 fast-growing individuals were selected, with average genetic gains of tree height, DBH and volume of 23.11%, 27.84%, and 96.77%, respectively. 【Conclusion】The tested families grow well at the sites, and the genetic variation in growth traits is abundant. The selected families and individuals can be promoted and applied in Fuding and similar site conditions in Fujian Province. This provides excellent genetic material for C. japonica afforestation, significantly increasing the afforestation area of improved varieties and enhancing the economic and social benefits of C. japonica plantations. In addition, it supports the construction of the second-generation breeding population of C. japonica and the advancement of its genetic improvement level.