Abstract: Effect of thinning intensity (heavy thinning, moderate thinning and unthinning) and times of thinning (thinning once or twice a rotation) on stand growth and timber outturn of Chinese fir (Cunninghamia lanceolata) were studied in Kaihua, Zhejiang Province. The first experiment was to cultivate big-diameter timber stand and thinned in the seventh year and fourteenth year, respectively, while the second experiment was to cultivate middle-diameter timber stand and thinned in the twelfth year. The results showed that there were no significant difference in tree height and total basal area among three thinning treatments in 22-year-old big-diameter timber stand and 19-year-old middle-diameter timber stand. The diameter at breast height (DBH) increased with the increase of thinning intensity. The average DBH value of big-diameter timber stand with heavy thinning and moderate thinning treatments increased by 13.78% and 9.69%, respectively, compared with the unthinned stand, while the DBH of middle-diameter timber stand with heavy thinning and moderate thinning treatments increased by 12.28 % and 7.02%. Thinning significantly increased the stem volume per tree, the living tree volume (LTV) of stand decreased with the increasing thinning intensity in the two experiments. In the first experiment, there was no significant differences in the LTV of 22-year-old stand among three thinning treatments (P>0.05). In the second experiment, the LTV of 19-year-old stand in the heavy thinning treatment was significantly lower than that in unthinned stand, there was no significant difference in LTV between the moderate thinning treatment and heavy thinning or unthinned treatments (P>0.05). The total stand volume (TSV) and total wood outturn (TWO) reduced with the increasing thinning intensity in the two experiments, there were no significant differences in TSV and TWO among the three thinning treatments (P>0.05). It is concluded that thinning intensity can not effectively increase the live tree volume and timber outturn, and the times of thinning has an important effect on timber outturn and timber size. For big-diameter timber cultivation of Chinese fir, twice thinning with 50% thinning intensity is appropriate in a rotation. It is suitable for middle-diameter timber cultivation with once moderate thinning (approximate 25%).