Objective: To screen novel genes related to adriamycin (Adr) resistance from human ovarian cancer resistance cell line OC3/Adr. Methods: Multidrug resistant ovarian cancer cell line OC3/Adr was induced by intermittent treatment of the human parent cell line OC3 with high concentration Adr. The difference of gene expression was screened by using different display analysis to the acquired Adr-resistance subline OC3/Adr and its parent cell line OC3. Results: OC3/Adr cell line was obtained which was more resistance to Adr than the parent cell line OC3 with the resistance index (RI) of 15.4. The OC3/Adr cell line also showed cross-resistance to other anti-cancer drugs (VP16, CDDP,5FU). It grew slowly and exhibited changes of cell cycle. A number of differentially expressed ESTs (Expressed Sequence Tags, ESTs) were identified at mRNA level between the OC3/Adr and OC3. Four of 18 different ESTs were sequenced. The 431/432 base pair S1 was homologous to human sperm zona pellucida binding protein, while the other two ESTs, S3 and S4, were new gene segments, which were registered to GenBank with the number of AF 117656 and AF 126507 respectively. Particularly, the expression of S2 sequence increased in all the drug-resistance cell lines and S3 sequence overexpressed in human ovarian cancer tissues as compared with benign ovarian tumors. Conclusion: Drug resistance induced by Adr in ovarian cancer OC3/Adr is involved with changes of multiple gene expressions.