Abstract: In order to fully utilize freshwater fish resources and develop new sources of elastin peptides, the basic information of the whole heart and bulbus arteriosus of three common bulk freshwater fish was measured in this study, including their mass, total nitrogen content in freeze-dried bulbus arteriosus, and content of desmosine (Des) and isodesmosine (Ide). Elastin peptides were prepared by enzymatic hydrolysis of bulbus arteriosus from different freshwater fish sources. Analyses of physicochemical properties of elastin peptides were conducted, such as the content of Des and Ide, whiteness, amino acid composition, peptide molecular weight distribution, and antioxidant capacity. The results showed that the average weight of the bulbus arteriosus of bighead carp was the highest, at 1.26 g/bulb, which was significantly larger than that of grass carp and silver carp arterial bulbs (P<0.05). The total nitrogen content of the freeze-dried bulbus arteriosus of silver carp was the highest, at 16.07%, while the total content of Des and Ide of the freeze-dried bulbus arteriosus ranged from 0.36% to 0.38%, with no significant difference among the three fish species (P>0.05). Among the three prepared elastin peptides, the yield of grass carp elastin peptides was the highest at 6.01%, while the yield of that for silver carp was the lowest at 4.13%. The total content of Des and Ide of the silver carp elastin peptides was the highest at 0.33%, which was significantly higher than that of the other two elastin peptides (P<0.05). Among the amino acid compositions of the three elastin peptides, glycine (Gly), alanine (Ala), glutamic acid (Glu), proline (Pro), and valine (Val) were the amino acids with higher content. Especially for grass carp elastin peptides, Gly content was as high as 26%, while histidine (His) and methionine (Met) contents were relatively low. However, there was no significant difference in hydroxyproline (Hyp) content (P>0.05), ranging from 2.36% to 2.41%. The essential amino acid contents of bighead carp elastin peptides were the highest, up to 27.77%. In addition, the proportion of peptides with molecular weight less than 500 Da in the elastin peptides of bighead carp was the highest, reaching 75.74%. Grass carp elastin peptides had the strongest ability to scavenge ABTS⁺ free radicals, with a clearance rate of 93.54% at a mass concentration of 2.0 mg/mL. The results show that freshwater fish bulbus arteriosus are potential advantageous raw materials for preparing elastin peptides, and there are certain differences in the properties of elastin peptides derived from different varieties of freshwater fish. The research provides a theoretical basis for the full utilization of freshwater fish resources and the development of high-quality elastin peptide products.