Our study on the half-sib progeny test started in 1972 and was completed in 1977-The results of this study show that the height growth in the nursery phase of the 45 families was very significant at the one percent level.The empirical value by manifested the genetype × environment interaction (GEI) can be detected by using covariance analysis. The high proportional Contribution of the variance components of family × year (7.39,%), family × site (7. 36%) and family × site × year (17. 91%) indicated that the GEI in Chinese fir was very significant.It is quitely advisable to explore GEI patterns by using half-sib progeny tests in the breeding program of Chinese fir.According to the results of the genetypic stability shown in this study, the families studied in the seed orchard can be divided into four classes, i. e, "fast growing stability", "medium stability", "variable" and "slow growing".