China’s 13th “Five-Year Plan” lasted from 2016 to 2020，when international risks soared due to the raging COVID-19 pandemic. The hot topics of public opinion and research topics of domestic ecology and environment have seen the interweaving of and transition from air pollution，haze control and pollution control to biodiversity，low carbon，nuclear safety，etc. This report sorts out the research results related to the “Trinity” public relations of the governments（enterprises），the media and the public under the theme of environmental protection in the past five years from the perspectives of policy interpretation on environmental protection，government function positioning，media means reconstruction，enterprises’ ecological concept，respondents’ role change and others. The report believes that over the past five years，researches on ecological and environmental protection and public relations are clear in objectives，diverse in means and rich in results. Through continuous inspections，researches and improvement in work，the governments’ image has been deeply rooted in the hearts of the people，the enterprises’ concept of environmental protection upgraded，and the public awareness of environmental protection improved.