Branched polymers as drug delivery carriers have been widely attempted due to their outstanding drug loading capability and complex stability like branched polyethyleneimine (B-PEI). However, branched polymers without biodegradability may cause toxicity as they can accumulate in the body. Herein, we report branched modified nonaarginine (B-mR9) composed of redox-cleavable disulfide bonds to form stable complexes with methotrexate (MTX) as an anticancer agent, which is further coated with hyaluronic acid (HA). The HA-coated nano-particles provide targetability for the CD44 cell surface receptor. The B-mR9-MTX/HA can effectively aid in intracellular MTX delivery to CD44 overexpressing cancer cells being degradable by the reducing environments of the cancer cells. The B-mR9-MTX/HA exhibits not only a glutathione-triggered degradability but also an outstanding CD44-mediated MTX delivery efficacy. In addition, its superior tumor inhibition capability was confirmed through an in vivo study. The results suggest that the HA-coated B-mR9 nanoparticle can be used as a drug delivery platform.