A novel series of acrylic resin/gelatin composite latexes (PA-G) with an ambient temperature self-crosslinkable function and excellent stability were prepared by seed, semi-continuous copolymerizing a functional monomer acetyl acetyethyl methacrylate (AAEM) with other normal monomers and adding a certain amount of gelatin as crosslinking agent into the resin emulsions (PA). FTIR spectra showed that the crosslinked structure had emerged in the composite films. Contact angles (CA), atomic force microscopy (AFM) and differential scanning calorimeter (DSC) were employed to characterize the PA-G films. The results indicated that the influences of AAEM-gelatin on some PA-G film properties differed greatly. Hardness and glass transition temperature (Tg) of PA-G films were both markedly enhanced, and tensile strength was evidently reinforced while elongation at break was in reducing trend. Suitable dosage of AAEM-gelatin crosslinked structure could render PA-G film with good water resistance, causing little change on its relative surface roughness.