According to the data of trashed length, micro fiber angle, air density, ring width and late wood percentage, with the analysis of optimum method of classification, the boundary line of juvenile wood and mature wood of planted Chinese fir (Cunninghamia lanceolata) was determined as the 14th year. Based on the variation pattern of these parameters, the prediction equations were established. Wood quality prediction can be realized by these equations. By error analysis between the values of measured data and the values of prediction data, it is found that the results of wood prediction of planted Chinese fire are satisfactory.