<正> Objectives. To detect telomerase activity in patients with mycosis fungoides （MF） and to study the role of telomerase in the tumorigenesis of MF.Methods. The technique of PCR-ELISA was employed to detect telomerase activity in 35 patients with various stages of MF.Results. 92.3% tumor stage of MF

78.6% plaque stage of MF and 75.0% patch stage of MF had positive telomerase activity. The control samples had no telomerase activity. Telomerase activity in tumor stage of MF was significantly higher than that in plaque stage

while the latter was higher than that in patch stage. Telomerase activity was correlated with the stage of MF.Conclusion. High level of telomerase activity frequently occurred in patients with MF

suggesting that telomerase might play an important role in the tumorigenesis of MF and is a useful marker for the diagnosis of MF possibly.