In order to improve alginate microbead stability and further broaden the application of alginate in biomaterials, a new biomaterial, ALG-g-Lys, was prepared and its possibility as a novel drug carrier investigated. The carrier exhibited a sustained release property and preserved activity with no initial burst release, and interestingly, GP-crosslinked ALG-g-Lys microspheres showed obvious fluorescence properties, which showed promising potential for the future drug delivery systems.