AIM: To find new biomarkers in the sera of retinoblastoma (Rb) patients with surface-enhanced laser desorption/ ionization time-of-flight mass spectrometry (SELDI-TOF-MS) and protein chip technique. METHODS: SELDI-TOF-MS, IMAC30 and CM10 protein chips were used to analyze the protein profiles from sera of 18 patients with Rb and 17 age-matched controls. The protein profiling was analyzed statistically by Ciphergen protein chip software 3.0.2. The Student's t -test was applied to compare the protein peak intensity. Fisher's exact test was used to compare the predominance of differential protein peaks appeared in patients. RESULTS: With IMAC30 protein chips, there were 26 proteins which appeared difference in sera of patients with Rb compared to normal children. Among them, 21 proteins, i.e. 7746, 7014, 11713, 3049, 7084, 7299, 5888, 2544, 12575, 5489, 9658, 9575, 9929, 10161, 8955, 1886, 10617, 6209, 2411, 7374, 6614m/z were up-regulated and 5 proteins, i.e. 8382,7923,7972, 8590, 66576m/z, were down-regulated (P < 0.01). Using the 7014m/z protein peak for statistical analysis, we could differentiate the patients with Rb from the healthy children with a sensitivity of 94.4% and a specificity of 82.4%. By CM10 protein chips, 4 proteins, including 3 up-regulated proteins (5888, 6097, 7798m/z) and 1 down-regulated protein (8590m/z), were detected in Rb patients (P <0.01). The sensitivity and specificity were 83.3% and 70.6% respectively when 7798m/z protein peak was selected for statistical analysis. CONCLUSION: There are a few candidates as Rb biomarkers in the sera of Rb patients. SELDI-TOF-MS protein chip technology could be a potential method in the clinical screening test of Rb.