Ovarian cancer is the second most frequently diagnosed gynecologic malignancy, and causes higher mortality than any other cancer in the reproductive system. Recognizing predictive markers of development and progression of this cancer would facilitate to individualize therapy and improve survival of ovarian cancer patients. Detection of genetic aberrations using array based comparative genomic hybridization (array CGH) has been implicated as one of important tools for identifying diagnostic and prognostic markers in various cancers, leading to the interesting study that exploration of copy number alterations in serous ovarian cancer at IIIc stage with the ultimate goal to discover potential predictive markers. To gain the best opportunities for exploring genomic imbalance involved in modulation of cancer development and progression, homogenous samples were selected as concerning with histology and stage in which we applied the array CGH with high resolution of one million formats. Here, the array CGH analysis obviously revealed significant DNA copy number changes (gain and loss) in Korean ovarian cancer patients at serous histological IIIc stage. We discovered DNA copy number gain in chromosome 6p22.3 whereas DNA copy number loss in chromosome 8p21.1-p12 and chromosome 11p15.4, with relatively high frequency of genomic alteration (83.3%). Upon these chromosomal regions, we eventually identified 32 genes including DUSP4, ID4, NRG1, and RRM1. We also classified their functions by gene ontology (GO) analysis using DAVID program and consequently demonstrated various interesting GO terms including biological regulation and positive regulation of cell growth. Taken together, these identified genes might be considered as potential predictive markers for further target-based strategies for diagnosis in Korean ovarian cancer patients at serous histological IIIc stage. These studies might also help understanding of tumorigenesis and the progression of ovarian carcinomas, in the aspect of genetic variations.