A growing number of companies, both multinationals and local firms, have begun to adopt the idea of sustainability development, and develop and market their green products/services with green advertising in developing countries. However, in the context of China where the idea of commercial environmentalism or green consumption is emerging and transported from the West, it is not clear that how the green consumption is advocated and how consumption practices are connected to environmental protection, and how the meaning of green consumption is constructed by firms operating in China. This study explores the Internet as a rich text for environmental marketing by analyzing the ways firms showcase details of their green products/services, production methods, business philosophy and other facets of their environmental practices and values. The online promotional information can be seen as corporate green advertising. Focused on the advertisings from corporate websites, and through the analytical framework of Critical Discourse Analysis (CDA) (e.g., Faircloug, 1992; 1995(a) (b); Wodak and Chilton, 2005), this study presents how a number of environmental conscious firms in China are portraying and promoting their environmental responsible image and green products/services, and aims to examine what firms are really telling and how they are discursively constructing corporate “greenness”. Based on the analyses of green advertisements from websites of four case companies (two MNCs in China: General Electric in China, Unilever in China, and two Chinese local firms: BYD automobile, and Landsea Real Estate), the study suggests that corporate green advertising discourse plays an active role in defining “reality” of greenness and imbuing meanings of consumption into environmentalism, as well as in achieving the hegemonic construction of corporate greenness. In addition, the corporate greenness is anthropocentric and embraces consumerist and post-materialist values. Instead of endorsing the environmentalism which appeals for a change of the current over-consumption lifestyle in capitalist development, the corporate green advertising strategically integrates lineages from green discourse of ecological modernization and political discourse of neoliberalism. In addition to similarities, dissimilarities existing between discourses from MNCs’ and Chinese local firms are identified in two aspects: greenness integration and greenness level. The differences in advertising discourses derive from both organizational resources and firms’ embedded economic, historical, and social-cultural contexts. Such differences prove the mutual constitutive or dialectical relationship between language and society and develop the argument that although firms play active role in constructing discourse, and green advertising discourse can be seen as corporations’ discursive approach to achieve environmental governance, their discourse is nevertheless constrained by both organizational internal and external influences.