Abstract: With socio-economic development, energy crisis has become a serious p roblem in the world. As a potential substitute plant for fossil fuel and a renew able energy, Jatropha curcas has been attracted particular attention. In thi s paper, a comparative study was made on the leaf nitrogen allocation, photosynt hesis, biomass accumulation and allocation, and seed yield of nine J. curcas populations, aimed to provide references for enlarging the planting of this spe cies and for breeding new varieties. The results showed there was a significant positive relationship between the photosynthesis and the fraction of leaf nitrog en allocated to photosynthetic apparatus. The final biomass of J. curcas was co-affected by photosynthetic and morphological traits, but biomass had no nec essary correlation with seed yield. Most of the photosynthetic and morphological parameters were significantly different among different J. curcas populatio ns, suggesting that there existed genetic difference among the populations. Howe ver, the difference in adaptability to growth environment was not the main reaso n for the genetic difference. Among the test populations, the population from Ru ili had better performances in physiology, biomass, and seed yield, being the pr eferable source for enlarging the planting of J. curcas and for the cross br eeding of new varieties. The appropriate growth environment and the stress-tole rant capability of this population needed to be studied further.

Key words: Pseudotaxus chienii, Population structure, Spatial distribution pattern, Community characteristics, Fengyangshan Natural Reserve