Abstract: Objective 　To explore the role of p38 in multicellular spheroid' s chemoresistance of ovarian cancer. Methods 　Const ruct eukaryotic p38 expression vector of full2length, t ransfect the vector, stably screen and culture it to form three dimensional multi2spheroids. The technique of RT2PCR and Western blot were applied to detect the expression of p38. Af ter the t ransfection of p38, we took the methods FACS and CCK28 to evaluate the sensitivity to cisplatin. Results 　(1) The expression of p38 was higher in A2780 monolayer cells than in it s multicellular spheroids. (2) When t reated with cisplatin, the apop2 tosis rate of spheroid t ransfected with p38 is higher than it s counterpart s by FACS. (3) The result s of CCK28 (Cell Counting Kit28) were similar to FACS ( P < 0. 05) . Conclusion 　p38 mediates the cisplatin effect s of ovarian cancer, and the up2regulation of p38 could increase the sensitivity of ovarian MCS to cisplatin.