Objective To study the effect of hyperthermia on expressions of multidrug resistance（MDR）genes intongue squamous cell carcinoma cell line Tca8113 and its MDR cell line Tca8113/CBDEA and intracellular ADM concentration. Methods Cell lines were hyperthermia-treated（42 ℃ for 0.5 h）, 4 h and 24 h later real-time quanti-tative reverse transcriptase-polymerase chain reaction（RT-PCR） detected expressions of MDR relative genes（MDR1, MRP1, GST-π）and HTS 7000 Plus Bio Assay Reader measured intracellular ADM concentration. Results Expres-sions of MDR1, MRP1, GST-π genes in Tca8113/CBDEA significantly descended at 4 h and 24 h post-hyperthermia（P
