Slogan has a sound mass base in China for thousands of years, functioning as guidelines for civic practice. Even today, Chinese slogans are often employed by the government to promote policies and socio-cultural values. This paper, adopting an ecolinguistic approach, explores the development of Chinese slogans during the four economic stages since the foundation of PRC (People's Republic of China) to find out how slogans influence the relationship between men, and man and the ecosystem. It is discovered that Chinese slogans in the recent decades have experienced great changes in terms of discourse type, the beneficial degree of discourse and the ecosophy they carry. They changed gradually from destructive discourse to harmonious discourse and they reflect the transition of Chinese ecological philosophy--from 'anthropocentrism', 'growthism', and 'classism' to 'harmonism'. It is hoped that this study can shed light on the eco-discourse analysis to policy language and will bring insight into its future creation.