The “3414” formula fertilization experiment was carried out on the third-generation Cunninghamia lanceolate seed orchard to explore the quantitative relationship between the seed yield of mother tree and the nutrient content of the corresponding needle，to study the action law of each nutrient and to determine the optimal nutrient content of the corresponding leaf when the seed yield is high，namely the nutritional diagnostic standard. It provides theoretical basis and practical guidance for scientific and rational fertilization and deficiency correction of seed orchards. The results showed that P，Mo and the interaction of N-Mo，P-K，K-Mg，Mg-Mo were the main factors affecting the seed yield of the third-generation seed orchard. Among them，Mo had a very significant negative correlation with seed yield (P<0.01). The interaction effects of N-Mo，P-K，K-Mg，Mg-Mo had significant promotion effect on seed yield (P<0.01). The optimum concentration range of the nutrient elements in the needles of the mother tree in the seed orchard was calculated by the optimum concentration method. The suitable concentration range of N，P，K，Ca，Mg，B and Mo in needles were 12.33～14.97 g·kg-1，3.26～9.04 g·kg-1，23.92～31.06 g·kg-1，9.10～12.34 g·kg-1，2.09～2.73 g·kg-1，28.42～46.50 mg·kg-1 and 0.12～0.38 mg·kg-1，respectively. According to the investigation and measurement results，the nutrient contents of mother tree needles with high yield in the seed orchard fell within the appropriate concentration range，indicating that the diagnostic standard had high reliability，which could provide reference for formula fertilization and deficiency correction in the third generation seed orchard of C. lanceolata.