Retinoblastoma (RB) shows cytogenetic aberrations involving genes other than RB gene located on 13q14. We analyzed genomic aberration in newly established RB cell lines SNUOT-RB1 and SNUOT-RB4 of adherent growth and Y79 cell line of nonadherent growth by microarray comparative genomic hybridization. SNUOT-RB1 showed 44 significant copy number changes (gain in 11 and loss in 33, P<0.0005). SNUOT-RB4 showed 42 significant copy number changes (gain in 8 and loss in 34, P<0.0005). Y79 cell line had the greatest gain of 19.65-fold in the locus of MYCN gene 2p24.1, whereas SNUOT-RB1 and SNUOT-RB4 showed no significant gain. SNUOT-RB1 and SNUOT-RB4 gained chromosomal copy numbers commonly in chromosome 11, especially in locus 11q13, which is responsible for cancer-related genes such as CCND1, MEN1, and FGF3. Losses of copy numbers occurred in chromosomes 3, 9, 10, 11, 16, and 17. In summary, SNUOT-RB1 and SNUOT-RB4 represented similar pattern in gain and loss of chromosomal copy number changes, while different from Y79. The loss of CYLD gene of tumor suppressor gene, 16q12-q13, was only on locus of common involvement in 3 cell lines.