Abstract: Environmental protection and human development have been being two major common issues faced by the international community. People have paid increasing attention to the negative impact of environmental degradation on women's survival and development, and have realized the great significance of women's participation in environmental protection to sustainable development and women's own development. This study discusses the profound relationship between gender and environmental issue, studies the formulation of policy on the gender mainstreaming in the international community as well as the status of applying the policy, and makes specific suggestions on how to advance gender mainstreaming in environmental projects. In view of the essential relation between gender and environmental issue, only gender mainstreaming is fully integrated into the full course of environmental projects, then it is feasible to eliminate gender discrimination during coordinating the relationship between man and nature, advance human equality, and accomplish the coordinated development of the human society and environmental protection.