Objective   To study the correlation between the genes of killer immunoglobulin (Ig)-like receptors (KIR) in natural killer cells and leukemia.    Methods   Primers of 16 KIR genes

including KIR2DL1-5

KIR3DL1-3

KIR2DS1-5

KIR3DS1 and 2 pseudogenes 2DP1 and 3DP1

were designed and synthesized. A polymerase chain reaction with sequence-specific primers (PCR-SSP) was developed to detect the mRNA expressions of the 16 genes. Totally 46 healthy individuals and 46 leukemic patients (15 cases of acute myelocytic leukemia

13 cases of chronic myelocytic leukemia and 18 cases of acute lymphocytic leukemia) were detected and the frequencies of the KIR genes were analyzed.    Results   The frequency of 2DL4

3DL2

3DL3 and 2DP1 in healthy and leukemic patients were 100%

and were detected in all patients and healthy individuals. The other KIR genes had similar frequencies except those of 2DL2 and 2DS2

which were 47.8% of the healthy individuals and  89.1% in leukemic patients. There was a significant difference between the 2 groups.   Conclusion   There may be an association between pathogenesis of leukemia and 2DL2 and 2DS2 genes.