[Objective] The aim was to study the proper altitude height and transplanting date around Shennongjia region. [Method] A field experiment with 15N isotope tracing micro-plots was carried out to study the effects of two different altitude heights (903 and 1 103 m) and three transplanting dates (May 5, 15 and 25) on nicotine concentrations and sources of nicotine-N in tobacco plants. [Result] The results showed that the proportion of fertilizer-N and soil-N which absorbed by tobacco plants, increased with the...