Abstract: Seeds and leaves of 5 natural populations of Jatropha curcas in Panzhihua area,Sichuan Province and 1 natural population from Yuanmou County,Yunnan Province were sampled and comparatively studied by means of nested variance analysis,correlation analysis,clustering analysis and other methods to reveal the phenotypic variation and rule of variability among the natural populations.The results showed that there was a great genetic variation both within and among natural populations in this region.The range of phenotypic differentiation coefficient among populations was 22.00%~72.63%,with the average value of 42.01%.The variation among populations was 42.01% that was less than the variation within the populations with 57.99%.The Miyi and Ganyu populations had a higher variation coefficient,i.e.,12.81% and 12.70% respectively.While Lazha and Tongde populations had a lower variation coefficient,which was individually 10.50% and 10.36%.The genetic repeatability of Miyi and Ganyu populations was 0.27 and 0.29 respectively,lower than the average value of 0.35.The 6 natural populations of Jatropha curcas in Panzhihua region were classified into 5 categories by UPGMA clustering with Ohm's distance among the populations,i.e.,the Ganyu and Miyi populations were grouped into one category,while each of the rest 5 populations was separately classified into its own category.