Somatic embryogenesis could be a powerful tool for rubber tree propagation and improvement. The CIRAD has developed a process to maintain embryogenic callus lines and produce somatic embryos. Three kinds of lines are obtained: Embryogenic and Regenerant (ER), Non Embryogenic (NE); which never give any embryos, or Embryogenic Non Regenerant (ENR); in which the embryos never germinate into plantlets. The characteristics of the lines are detected late in the course of the regeneration process, whereas we suspect an early determination of the embryogenic capacity. In order to develop a rapid screening method to select the ER lines, more information had to be obtained on the underlying mechanisms of somatic induction. To complete the histological knowledge of our material, a molecular study of gene expression has been undertaken. This study is focused on the early steps of embryogenesis (the 14 days after induction). We compared the mRNA patterns of an ER line at different times during the course of induction. We also compared different lines at the end of the proliferation step, just before induction.