Injectable hydrogels provide the advantage of moldability to fill irregular-shaped wounds compared with pre-formed hydrogels. We previously reported the usefulness of sugar beet pectin (SBP) as an injectable hydrogel material. For application of the SBP hydrogel to wound care, the hydrogel needs to enhance tissue adhesiveness and have an efficacy for promotion of wound healing. To this end, chitosan-gluconic acid conjugate (CG) was incorporated into SBP hydrogel. We showed that the SBP/CG aqueous solution rapidly formed hydrogel (< 1 min) via a horseradish peroxidase-mediated oxidative reaction. The tissue adhesiveness of the SBP/CG composite hydrogel was greater than that of a plain SBP hydrogel. The composite hydrogel promoted infiltration of polymorphonuclear leukocytes, which is an important step to promote wound healing. Furthermore, the incorporation of CG enhanced degradation of the hydrogel is promising in the care of ulcers and erosions of digestive system. These results show that the composite hydrogel is useful as an injectable wound dressing.