Abstract: In order to explore the effects of different cultivation methods on burley tobacco nicotine conversion rate and TSNA content, A split plot experiment with three replicates was designed to determine light intensity, alkaloid content, nicotine conversion and four kinds of TSNA content in a comparative analysis. The results showed that, conversion rate difference between varieties is a major factor affecting TSNA content. Significant influence of TSNA content was also observed by planting with different specifications, and perpendicular to the ridge or parallel on the ridge. There is also a significant interaction effect between variety and row direction and planting specification. HC varieties were affected more significantly by planting specifications than LC varieties. Formation and accumulation of alkaloid metabolites and TNSA are likely affected by light intensity. Effective measures to reduce the content of TSNA in tobacco leaves include using low conversion rate varieties, good cultivation practices and appropriate row direction to improve light conditions of tobacco plants.