To study the effect of α1,2-fucosyltransferase gene transfection on p38MAPK signaling pathway- mediated apoptosis in ovarian carcinoma RMG-I cells. The localization of p38MAPK and p-p38MAPK was detected by immunofluorescence in RMG-I and RMG-I-H cells. The expression of p38MAPK and p-p38MAPK was analyzed by RT-PCR and Western blot, respectively. For inhibition assay, anti-Lewis y antibody was used to assess the change of p38MAPK of mRNA level in RMG-I-H cells by RT-PCR and Western blot. Using 0.1%DMSO as control, the apoptosis rate was detected by flow cytometry(FCM) in SB203580 treated RMG-I-H cells. Simultaneously, the expression of p38MAPK and caspase-3 was analyzed by RT-PCR and Western blot. Further more, the expression of p38MAPK and caspase-3 by RT-PCR after Carboplatin and/or SB203580 treatment were studied. Results showed that immunofluorescence staining of p38MAPK and p-p38MAPK in RMG-I and RMG-I-H cells showed cytoplasmic localization and nuclear localization, respectively, and the level of p-p38MAPK mRNA in RMG-I-H cells is significantly higher than that in RMG-I cells(P < 0.05), while the expression of p-p38MAPK mRNA decreased after anti-Lewis y antibody treatment (P < 0.05). FCM showed that the apoptosis rate increased in SB203580 treated RMG-I-H cells(P < 0.05). The mRNA level of p38MAPK and caspase-3 increased by treatment with Carboplatin. The mRNA level of caspase-3 also elevated by treatment with SB203580. In conclusion, high expression of Lewis y inhibits apoptosis in ovarian cancer cells, probably due to involvement of Lewis y in regulating p38MAPK signaling pathway, thereby causing drug resistance.