A number of nanoparticle (NP)-based drug delivery systems for cancer therapy have been found to be predominantly located near the blood vessels and to deliver the drug to the periphery of tumor due to the physiological barriers of the solid tumor [1].The non-uniform distribution of the anticancer drugs throughout the tumor increases the difficulty for radical cure of cancer.To facilitate the uniform distribution of drugs throughout the tumor,we have fabricated a reversible swelling-shrinking nanogel (NLSC-NG) as a sequential intra-intercellular Np delivery system,which has accomplished deep tumor penetration via i.v.injection [2].However,lack of a specific ligand for tumor cells impedes the mass accumulation of the NLSC-NG within tumors via i.v.injection.Intratumoral (i.t.) injection of NP has been explored in cancer therapy because of the distinguished advantages of longer exposure time in the tumor mass and less systemic exposure.Herein,we focus in this work on the i.t.injection of NLSC-NG with the aim of deep tumor penetration.