The objectives of this study were to comparison and selected the hybrids of stem size, and the correlation coefficients between stem size and biomass yield. A total 13 lines of F1 hybrids between Jatropha curcus and J. integerima with J. curcus (M10) were evaluated in field trials. Data were collected for stem size, primary branch, secondary branch and tertiary branch at 7 and 12 months and biomass yield in fresh weight and dry weight at 12 months. The stem size and branch showed difference in significance and select varieties KUJBL14 and KUJBL13, which give biggest the diameter stem and branch. Moreover, the correlation coefficients between the diameter stem and biomass yield (r = 0.69** to 0.95**) was positive and significant. The variety had a diameter stems and branches were high biomass yield. Therefore, the stem size and branches are important characteristics in selection of Jatropha. These crosses can be useful in Jatropha breeding project.