Peach kernel peptides and ferrous chloride as raw materials. The chelating rate of different food peptides， iron salts and different molecular weight peach kernel peptides were studied， as well as the structural characterization and variations of PKP3-Fe complex in vitro simulating digestion were studied. The chelating rate of peach kernel peptides with ferrous ions was significantly higher than that of soybean peptides， corn peptides and fish collagen peptides（P<0.05） and the low molecular peach kernel peptide component has highest chelating rate. The positions and peak value of UV absorption peaks of peach kernel peptides changed after chelated with ferrous ions， and the intensity of endogenous fluorescence decreased obviously. Fourier transfer infrared spectra suggested that the -COO-， N-H， C-N， O-H of peptide could participate in the chelation of peptide with ferrous iron. The results of SEM demonstrated that PKP3-Fe has smooth spherical particle structure. During simulating gastric digestion， the ferrous iron release rate of PKP3-Fe was significantly lower than that of ferrous sulfate and ferrous lactate （P<0.05）， which can avoid the formation of a large amount of ferric hydroxide precipitation. After entering simulating intestinal digestion， part of PKP3-Fe was in ionic or chelate state. The absorption in body of peptide-ferrous complexes could be better than ferrous sulfate and ferrous lactate.