We obtained human IL-2R cDNA 673 bp fragments from plasmid pJSB15 and prepared ?-32 p-IL-2 R cDNA probe. Dot hybridizations of RNA extracted from human lymphocytes were done by using the probe. The results showed that PHA or TPA could induce IL-2 R mRNA, respectively; and the synergistic effects were seen when used them together. IL-2R mRNA could be expressed spontaneously in many kinds of leukemic lymphocytes isolated freshly from PBL of leukemic patients.