The eight clones of Chinese fir complete diallel crosses of 32-year-old forest's tree height,DBH and volume for test the advantages of hybrid and inbred fading effect analysis,and the combining ability variance and combining ability effect value were calculated.The result show that:true genetic variation exists in three traits,general combining ability, special combining ability,positive and negative cross effect variance all reached significant level,and volume to special combining ability of the genetic variance ratio (GVC)is maximum.Selected three excellent clones for hybridization and two growps of excellent clones for Bi-clonal seed orchard,and 19 combination of cross superior trees for second generation.