Background/Aims: To evaluate the relationship between chemosensitivities in vitro and expressions of multidrug resistance (MDR) associated factors in differentiated gastric carcinomas. Methodology: Gastric carcinomas tissues of varying degree of differentiation (65 cases) were collected and chemosensitivities to 5-FU, HCPT, PTX, L-OHP, CDDP and eADM were detected by sulphorhodamine B (SRB) assay, and expressions of P-gp, GST-pi, Topo H alpha, p53, Bcl-2, Bax and Survivin were tested by immunohistochemical staining. Results: Inhibition rates of 5-FU, L-OHP and CDDP for well differentiated tumors were lower than those of poorly differentiated tumors (p<0.05). Expressions of P-gp, Bcl-2 and Survivin were higher in well differentiated than in poorly differentiated carcinomas (p<0.05); while expression of Topo Ha in well differentiated carcinomas was lower than in poorly differentiated carcinomas (p<0.05). The expression of MDR factors was different between well and poorly differentiated carcinomas. Conclusions: Different MDR characteristics were exhibited in well and poorly differentiated gastric carcinomas, which may be caused by different expressed MDR associated factors in these tissues.