Effects of altitude, sunshine condition and some cultivation factors on nicotine conversion in burley tobacco were studied. Results showed that nicotine conversion rate declined as altitude increased in west Hubei and the best quality and lowest nicotine conversion rate appeared at 1000 m altitude. Plenteous sunshine could distinctly decrease nicotine conversion rate. The increasing plant space was in favor of decreasing nicotine conversion rate in low leaves and the increasing row space was in favor of decreasing nicotine conversion rate in upper leaves. The nicotine conversion rate in upper leaves increased as topping period delayed. The nicotine conversion rate slightly increased as topping from early bud to full bud period and declined from full bud to early flower period in lower leaves. The remaining leaf number was negatively correlated with nicotine conversion rate. The harvest way of stalk-cutting was in favor of decreasing nicotine conversion rate and the picking up opposite. Medium level of RH was in favor of decreasing nicotine conversion rate in middle and low leaves while higher RH, the upper leaves.