【Objective】The present experiment was conducted to study the effect of different planting densities on the free amino acids content and quality of burley leaves and to determine the optimum planting density in order to optimize the cultivation technology for burley. 【Method】The OPA/FMOC derivatized amino acids method using reversed phase high performance liquid chromatography was used to determine the free amino acids content in leaves of burley plants grown with different planting densities. 【Result】The order of the effects of planting density on the contents of 17 free amino acids in burley leaves was as follows: Asp＞Ser＞Phe＞Glu， Gly， His， Arg+Thr， Ala， Pro， Tyr， Met， Lys and Leu＞Val＞Ile＞Cys-2. The total content of free amino acid increased initially， followed by a decrease with increasing planting density. The maximum content of total free amino acid was obtained in treatment 5 （row spacing 110 cm×45 cm， planting density 20190 plants/ha）， followed by in treatment 6 （row spacing 120 cm×40 cm， planting density 20835 plants/ha）. The minimum content of total free amino acid was obtained in treatment 9 （row spacing 100 cm×40 cm， planting density 25005 plants/ha）. The burley leaves in treatment 4 （row spacing 100 cm×50 cm， planting density 19995 plants/ha） were found to have the best total score with nice aroma quality， high aroma quantity， lesser miscellaneous gas and weaker irritability. The lowest total score was found in treatment 1 （row spacing 120 cm×50 cm， planting density 16665 plants/ha）. 【Conclusion】The planting density highly affected the contents of Asp， Ser and Phe in leaves， while the contents of Val， Ile and Cys-2 were least influenced by planting density. The quality of burley leaves could be obtained by planting it in 110 cm×45 cm row spacing with 20190 plants/ha planting density.