A method for the simultaneous obtention of heparin, proteins and peptides in native state by fractionation of mammalian intestine mucosa, comprising the following steps: (i) adding to an aqueous extract of mammalian intestinal mucosa a preservative and antioxidant agent to obtain a preserved mucosa, or preserving the extract at a temperature allowing preserving proteins, peptides and heparin in native state; (ii) optionally diluting the preserved mucosa with up to 100 volumes of deionized water, to obtain a diluted mucosa (iiia) submitting diluted mucosa of step (ii) or preserved mucosa of (i) to homogenization at a temperature of less than 40 °C, optionally in presence of detergents and/or hydrolytic enzymes such as phospholipases, to lyse cell membrane of mucosa cells to obtain a stable homogenate of the mucosa comprising heparin and mucosa proteins and peptides; (iva) separating heparin and the mucosa proteins and peptides contained in the stable homogenate obtained in step (iiia) by one or more of physical and/or chemical means selected from the group consisting of centrifugation and filtration (microfiltration and/or ultrafiltration), optionally using detergents, and combinations thereof, to obtain a pellet or retentate fraction comprising heparin and proteins; and a supernatant or permeate fraction comprising mucosa proteins and peptides; (v.a') submitting the pellet or retentate fraction of (iva) comprising heparin to an alkaline proteolytic process by means of proteolytic enzymes to obtain a mixture of heparin and a protein hydrolysate, submiting the mixture with heparin to one or more precipitation steps, and optionally to one or more of extractive steps, and to one or more of a chromatography to purify the said heparin from the protein hydrolysate; and (v.b') submitting the supernatant or permeate of (iva) comprising a mixture of solubilized and/or suspended mucosa proteins and peptides to one or more of successive filtration, ultrafiltration steps, solvent extraction, protein precipitation, enzymatic hydrolysis, gel permeation, ion exchange chromatography, size exclusion chromatography, or affinity chromatography steps, being exchangeable the order or sequence of the steps, in order to separate the proteins and peptides according to any of their solubility, isoelectric point and/or molecular weight. (i) adding to an aqueous extract of mammalian intestinal mucosa a preservative and antioxidant agent to obtain a preserved mucosa, or preserving the extract at a temperature allowing preserving proteins, peptides and heparin in native state; (ii) optionally diluting the preserved mucosa with up to 100 volumes of deionized water, to obtain a diluted mucosa (iiia) submitting diluted mucosa of step (ii) or preserved mucosa of (i) to homogenization at a temperature of less than 40 °C, optionally in presence of detergents and/or hydrolytic enzymes such as phospholipases, to lyse cell membrane of mucosa cells to obtain a stable homogenate of the mucosa comprising heparin and mucosa proteins and peptides; (iva) separating heparin and the mucosa proteins and peptides contained in the stable homogenate obtained in step (iiia) by one or more of physical and/or chemical means selected from the group consisting of centrifugation and filtration (microfiltration and/or ultrafiltration), optionally using detergents, and combinations thereof, to obtain a pellet or retentate fraction comprising heparin and proteins; and a supernatant or permeate fraction comprising mucosa proteins and peptides; (v.a') submitting the pellet or retentate fraction of (iva) comprising heparin to an alkaline proteolytic process by means of proteolytic enzymes to obtain a mixture of heparin and a protein hydrolysate, submiting the mixture with heparin to one or more precipitation steps, and optionally to one or more of extractive steps, and to one or more of a chromatography to purify the said heparin from the protein hydrolysate; and (v.b') submitting the supernatant or permeate of (iva) comprising a mixture of solubilized and/or suspended mucosa proteins and peptides to one or more of successive filtration, ultrafiltration steps, solvent extraction, protein precipitation, enzymatic hydrolysis, gel permeation, ion exchange chromatography, size exclusion chromatography, or affinity chromatography steps, being exchangeable the order or sequence of the steps, in order to separate the proteins and peptides according to any of their solubility, isoelectric point and/or molecular weight.