Abstract: With the objective to clarify the genetic parameters of growth and cold tolerance in interspecific hybrids between Eucalyptus urophylla S. T. Blake and E. dunnii Maiden, a factorial mating population of the two species was investigated on 8-month-old cold tolerance(C₈)as well as 20-month-old growth traits height(H₂₀)and diameter at breast height(D₂₀). For all the three traits measured, the variance components of E. urophylla female, E. dunnii male and female×male interaction were not significant, in which the interaction was the main source for C₈ while both the female and interaction effects contributed to growth(H₂₀ and D₂₀), with the female effect at a higher magnitude. Narrow-sense heritability(h²)values of C₈, H₂₀ and D₂₀ were 0, 0.29 and 0.22, respectively, indicating little genetic control of cold tolerance but moderate genetic control of growth. Except the significant phenotypic correlation(P<0.05)between H₂₀ and D₂₀, all the rest phenotypic and additive genetic correlation coefficients were not significant among traits. Female general combining ability(GCA_F)and general hybridizing ability(GHA_F)were weakly correlated. In addition, female-parent heterosis values were calculated. It was concluded that the h² values for all the traits were markedly small and selection of superior hybrids and individuals would be appropriate in breeding practices.