Abstract: To explore nitrogen amount and planting density on the production and quality of cigar, and CX-81 was selected as the research object,the effects of three different nitrogen application levels of 142.5 kg/hm²（N1）, 172.5 kg/hm²（N2）, 202.5 kg/hm²（N3）, and three densities of 18 180 plants/hm²（D1）, 20 205 plants/hm²（D2）, 22 725 plants/hm²（D3） on the contents of chlorophyll, economic characters, chemical components after air-during of cigar were studied. At the same time, the correlations of chlorophyll content and the chemical components of cigar were analyzed. The results showed that with the increase of planting density, the contents of chlorophyll, total sugar, reducing sugar and the ratio of total sugar to nicotine decreased gradually, and nicotine and total nitrogen increased with the increase of nitrogen application, while chlorophyll, reducing sugar and total sugar were the highest in N2 level. The content of chlorophyll in the middle cigar leaves was positively significant correlated with total sugar and reducing sugar. The nitrogen application amount and density had significant difference on nicotine, total nitrogen, total sugar, reducing sugar, nitrogen-alkali ratio and sugar-alkali ratio of cigar, but the interaction of the two just had significant difference on total nitrogen and the ratio of nitrogen to alkali. The higher nitrogen application could obtain a larger single leaf weight and yield, but it affected the quality of tobacco. The smaller planting density was beneficial to the quality of tobacco, but it affected the yield. It was suggested that the nitrogen application amount should be 202.5 kg/hm² in the low density （D1） planting area, and 172.5 kg/hm² should be selected in both D2 and D3 planting area.

Key words: cigar, nitrogen amount, planting density, cooperation effect, chlorophyll, production and quality