Abstract: The IL-2 lovel of PBMC production on 25 patzents with alopecia areata (AA).frond decreased significantly in comparison with 35 normal donors (ND)(68.2+26.0U/ml, 102.4+23.7U/ml respectively)P<0.0005. When the macrophases of ND were added to the PBLC of AA patients, the IL-2 activity increased significantly, the level of IL-2 dropped when the macrophages of AA patients were put into the PBLC of ND. These results imply that the function of macrophages is abnortrtal in patients with AA. The level of macrophage production IL-1 activity was very rose (P>0.5) both in ND and AA. After extra PGE2 was added into PSMC (ND or AA), the resin is showed that PGF2 down-regulated IL-2 in ND and, in a lesser extent, in AA. On the contrary, after indomethacin, a PGE2 antagonist, was put into P13MC, the results indicated that the drug up-regulated IL-2 in patients and, in a lesser extent, in ND. Put the PBLC of AA in vitro for 24 hours or mare the IL-2 activity restored to normal at least for 72 hours, the cause and significance remain to be studied.