Epidermal growth factor (EGF, 5900 Da) has been reported to have the high efficiency of wound repair. However, the half-life of EGF in the body is too short to exert the biological activity effectively when applied in free forms. Conjugation of the low molecular weight chitosan (LMC) to EGF was carried out to enhance its stability. EGF was conjugated with LMC activated by water-soluble carbodiimide. The formation of EGF-LMC was quantitatively measured by indirect enzyme-linked immunosorbent assay (ELISA). In a study of the thermal and the proteolytic stability of free EGF and EGF-LMC, EGF covalently attached to LMC was found to be more stable than free EGF in thermal and proteolytic stabilities. In animal experiments of which free EGF (control), EGF-LMC (test) and LMC (carrier) diluted in viscous carboxymethyl cellulose (CMC) solution (vesicle) were applied to the incisional wounds in rats, the EGF-LMC conjugates are considered to be potent wound healing agent with mitogenicity and wound-healing property. (c) 2006 Wiley Periodicals, Inc.