Abstract: The computer model on the management of Chinese Fir (Cunninghamia lanceolata (Lamb.) Hook) plantations is based on the growth tables, while the influences of site preparation, tending and thinning methods on tree growth were taken into consideration. The light competition was evaluated by a crown influence coefficient which was a function of crown overlaping index. The data of 71 surveyed plots were used to validate the model by F-test and U-test. The critical value of F was 3.13, while the F-values for diameter, height and volume were 4.60, 0.60 and 1.87 respectively. This means that only the diameter had a systematic tendency of being slightly underestimated by the model, taking α=0.05. The U-values for the differences between predicted and practical diameter, height and volume values were 0.51, 0.03 and 0.33 respectively, taking α=0.05 in the U-test. Therefore the hypothesis of the differences being zero was acceptable. The accuracy of prediction was regarded as good. The model is suitable for the middle region of Chinese fir distribution in China. The model can be used as a forest growth predictor. Because that it contains economic analysis and can also be used for the theoretical calculation of optimization for different combinations of managerial measures.