The relationship between the nicotine content in 222 flue-cured tobacco samples and organic matter,total N,available N in soil from Hunan tobacco-growing areas was analyzed.The results indicated that:(1) The nicotine content in flue-cured tobacco leaf showed a big variation among different grades,and showed the trend of B2F>C3F>X2F in total.The content of nicotine ranged from 0.58% to 5.95%,with mean of 2.84% and variation coefficient of 34.07%.(2) The correlation coefficients of the nicotine content among different grades and the three kinds of soil nutrients including organic matter,total N and available N were all significant at 0.01 level,respectively;and their corresponding regression equations were built.(3) Based on content of nicotine and by using cluster analysis method,the same grade tobacco samples could be divided into three groups of high,medium and low content with different levels.Comparing different clusters,the higher the soil organic matter was,the higher the soil total N,soil available N were,and corresponding content of nicotine was also.The result showed that the contents of soil organic matter affected the supply of the soil nitrogen elements and ulteriorly affected the accumulation of nicotine in tobacco leaf.