Genetic variations on traeheid microfibril angle of 55 Chinese fir clones were investigated. The results revealed that microfibri[ angle had a highly significant difference among clones. The broad sense heritability estimates of clones varied between 0. 734 and 0. 867,indicating the microfibril angle was under strong genetic control. The average genetic gains were 19. 51% for the microfihril angle if 10% of the best clones was selected. The microfibril angle decreased with increase of growth ring age and the microfibril angle at the 10th ring was about 32. 1% less than that at the 1St ring. The microfibril angle showed a highly significant difference among different rings. The correlations coefficients of microfibril angle between different tree ages since 3rd growth ring were very significant indicating that early selection for the microfibril angle would be efficient.