This article reviews the development of environmental NGOs （ENGOs） in China during the past 30 years and explains the unique roles played by ENGOs in the development of the environmental legal system in China，including enhancing people’s consciousness of environmental law，promoting public participation，influencing public decision-making，supervising over the acts of various social subjects，promoting the implementation of environmental law，participating in legislation and government decision-making，initiating environmental public interests litigation，and upholding people’s environmental rights and interests. Currently the main factors preventing ENGOs from giving full play to their roles in China include：the defective NGO administration mode，the lack of self-construction on the part of NGOs themselves，and restrictive financial and tax systems. This article focuses on the analysis of the legal standing of ENGOs in environmental public interest litigation，and points out that，in developing the environmental legal system，China should vigorously support public interest litigation initiated by ENGOs，give more litigious rights to NGOs，and establish corresponding implementation mechanisms，such as rules on the exercise of litigious rights by ENGOs，on the producing of evidence，on expert witness，and on court costs.