Abstract:No. 244 and No. 5 open-pollinated seeds of Chinese fir (Cunninghamia lanceolata) collected from a primary seed orchard were used as the test material, for studying the effect of nitrogen metabolism on seed vigor of during germination (including germination speed, seedling weight, content of free amino acids and protein, etc.), seventeen kinds of free amino acids of Chinese fir seeds, which were not changed during germination but the content were changed constantly, were determined and analysed. Dry seeds used in treatments soaked in 2% NH4Cl solution for 30 minutes at 40℃. It was shown that germination speed, contents of 5 kinds of free amino acids and embryo protein, etc, during the germination were higher than that in control. In addition, contents of free amino acids in endosperm and embryo of the highvigor seeds during germination were higher than those in low ones.