Abstract: Objective: Our purpose is to study whether hyperthermia combined with cisplatin enhances drug sensitivity and reverses drug resistance in ovarian cancer cell lines. Methods:MTT was used to study the cell proliferation and inhibi-tion rates in SKOV 3 and cisplatin-resistant SKOV 3/DDP cells. We estimated the expression of the ERCC 1 gene in SKOV3 and SKOV 3/DDP cells by Western blotting to analyze the mechanism of hyperthermia combined with cisplatin. Results: ① At less than 41℃for 90min and 120 min, the inhibitory effects of cisplatin on SKOV3 cells are statistically significant ( P< 0.001 ). At less than 41℃at various times, the inhibitory effects of cisplatin on SKOV3/DDP cells are statistically significant (F=18.135 , P<0.001 ). ②Comparing the hyperthermic effect of cisplatin at room temperature and at41℃at various times, the sensitivity of cisplatin on SKOV 3 cells was significantly different (F=67.489 , P<0.001 ). At 41℃and 90min the sensitivity was higher than at60min (P=0.002 ). The sensitivity to cisplatin by SKOV 3 cells was increased 79.885 %, and the sensitivity to cisplatin on SKOV3/DDP cells was significantly different ( F=18.356 , P<0.001 ). The sensitivity of cisplatin on SKOV 3/DDP cells was increased 37.129 %. The sensitivity to cisplatin was higher at41℃than at room temperature. ③The expression of the ERCC 1 gene in SKOV3 was significantly lower than in SKOV3/DDP (F=32.175 , P<. 001 ), but there was no difference in expression of ERCC 1 in SKOV 3 and SKOV 3/DDP cells between room temperature and 41℃(30min, 60min, 90min and 120 min) (F=0.962 , P=0.443 ). Conclusion : Thermotherapy has an inhibitory effect on SKOV 3 and SKOV 3/DDP cells. Ther -motherapy increased the sensitivity of SKOV3 cells to cisplatin and reversed the drug-resistance of SKOV 3/DDP. The opti -mal experimental conditions were 41℃and 90min. The expression of ERCC1 in SKOV 3 cells was lower than SKOV3/DDP cells, but there was no difference between the cells at room temperature and the four time points at 41℃in either SKOV 3 or SKOV3/DDP cells. Hyperthermia increases the sensitivity of SKOV 3 to cisplatin and reverses the drug-resistance of SKOV 3/DDP.