Collagen peptides from tilapia skin were prepared by enzymatic hydrolysis with protamex, and effects of activated carbon and macroporous adsorption resin on decolorizing of peptides were investigated. Based on the decolorizing rate and peptide loss, the optimum decolorizing conditions of collagen peptides were determined by orthogonal test. The results showed that the optimum decolorizing conditions of activated carbon were pH 4.5, 2% (m/V) activated carbon dosage, decolorizing time of 60 min and protein concentration of 50 mg/mL. Under those conditions, the decolorizing rate and peptide loss of collagen peptides were 92.66% and 11.23%, respectively. However, the decolorizing effect of macroporous adsorption resin was significantly inferior to activated carbon, which the decolorizing rate and peptide loss of collagen peptides were 83.02% and 30.77%, respectively. Based on the results of the molecular weight distribution and amino acid composition, it was found that both component ratio of 500～1 000 Da and amino acid conent of His, Tyr or Phe were significantly decreased after decolorizing whether with activated carbon or macroporous adsorption resin.