Environment-responsive polymeric nanoparticles as antitumor drug delivery systems could response to tiny environmental stimulus, change their structure and release the antitumor drug. They have been widely applied in biomedical area due to their considerable advantages of prolonging survival time with lower toxicity, controllability and high drug loading in cancer therapy. Here, we present an overview of the recent work on environment-responsive polymeric nanoparticles as drug delivery systems for cancer therapy, including pH sensitive, temperature sensitive, redox sensitive and enzyme sensitive, based on the domestic and international research progress. In addition, recent advances and future directions in the development of environment- responsive polymeric nanoparticles as antitumor drug delivery systems are also included.